docs: improve README, config reference, API docs, and contributing guide

[tinu-hareesswar]

Summary

• README.md: Added CI/release/license badges, tightened value proposition, removed unfounded perf claims, added concrete feature list (Priority Logic V2, hedging, debit routing), working Docker quick-start with copy-pasteable curl examples, routing strategies section
• docs/configuration.md: Expanded from 69-line stub to full reference covering all config sections (server, metrics, logging, database, redis, cache, routing_config, debit_routing, secrets_manager, env overrides)
• docs/api-reference.md: Replaced 9-line redirect with endpoint map covering routing, feedback, health, rule CRUD, merchant CRUD, Priority Logic V2, with pointers to OpenAPI spec and Postman collection
• CONTRIBUTING.md: Fixed broken CODE_OF_CONDUCT.md link, corrected repo URLs, added Contributor Covenant statement and security contact

Test plan

• Verify all internal doc links resolve correctly
• Confirm quick-start Docker commands work end-to-end
• Review configuration reference against actual development.toml

🤖 Generated with Claude Code

[Copilot]

Pull request overview

This PR refreshes the project’s documentation to provide clearer onboarding, a more complete configuration reference, and a navigable API overview.

Changes:

• Expanded docs/configuration.md into a detailed configuration reference (sections, precedence, env overrides, examples).
• Reworked docs/api-reference.md into an endpoint map with links to OpenAPI and the full api-reference1.md.
• Updated README.md and CONTRIBUTING.md with improved quick start, links, and contributor guidance.

Reviewed changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated 6 comments.

File	Description
docs/configuration.md	Converts a stub into a full config reference with section-by-section examples and override guidance.
docs/api-reference.md	Adds an endpoint map and pointers to OpenAPI/Postman/full API reference.
README.md	Updates badges, value prop, feature list, quick start, and documentation pointers.
CONTRIBUTING.md	Updates contributor guidance, setup pointers, and conduct/security contact info.

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[Copilot]

The [limit] section is documented as a “coarse global rate limiter”, but in the code it is behind the limit feature flag and the rate-limiting middleware is only applied to the /delete route (see src/routes/data.rs). This section should document the feature-gating and scope accurately, or be removed from the default configuration reference if it’s not part of the standard builds.

[Copilot]

The secrets configuration section does not match what the service deserializes. The config struct expects [secrets_management] with a secrets_manager = "..." key (see src/config.rs tests), not [secrets_manager] with secrets_management_config. As written, this example won’t work and should be updated to the actual TOML shape and enum values used by SecretsManagementConfig.

Suggested change

	### `[secrets_manager]`
	Controls how secrets (DB credentials, gateway keys) are resolved at boot.
	```toml
	[secrets_manager]
	secrets_management_config = "no_encryption" # no_encryption | aws_kms | hashicorp_vault
	### `[secrets_management]`
	Controls how secrets (DB credentials, gateway keys) are resolved at boot.
	```toml
	[secrets_management]
	secrets_manager = "no_encryption" # no_encryption | aws_kms | hashicorp_vault

[Copilot]

The environment-variable override prefix/pattern in this table appears incorrect. The config loader uses config::Environment::with_prefix("DECISION_ENGINE") with separator("__") (see src/config.rs), so overrides should be DECISION_ENGINE__REDIS__HOST, etc., not ROUTER__…. This section should be updated to the correct prefix (and ideally note that the config crate applies these overrides generally, not only “when explicitly supported”).

[Copilot]

A few paths/parameter names in the endpoint map don’t match the OpenAPI spec (docs/openapi.json). For merchants, the path parameter is {merchantId} (not {id}); for routing rules, the paths are /routing/list/{merchantId} and /routing/list/active/{created_by}. Updating these will keep the map consistent with the canonical spec.

Suggested change

	| | `GET /merchant-account/{id}` | Retrieve a merchant |
	| | `DELETE /merchant-account/{id}` | Delete a merchant |
	| **Priority Logic V2** | `POST /routing/create` | Create a routing algorithm |
	| | `POST /routing/evaluate` | Dry-run an algorithm against a payload |
	| | `POST /routing/activate` | Make an algorithm the active one |
	| | `POST /routing/list/{merchant_id}` | List all algorithms for a merchant |
	| | `POST /routing/list/active/{merchant_id}` | List the currently active algorithms |
	| | `GET /merchant-account/{merchantId}` | Retrieve a merchant |
	| | `DELETE /merchant-account/{merchantId}` | Delete a merchant |
	| **Priority Logic V2** | `POST /routing/create` | Create a routing algorithm |
	| | `POST /routing/evaluate` | Dry-run an algorithm against a payload |
	| | `POST /routing/activate` | Make an algorithm the active one |
	| | `POST /routing/list/{merchantId}` | List all algorithms for a merchant |
	| | `POST /routing/list/active/{created_by}` | List the currently active algorithms |

[Copilot]

The “Build from source” snippet mixes cargo build --release ... with cargo run ... using different feature sets (and without --release), which will trigger a separate debug rebuild and can confuse readers about which binary they’re running. Consider either using cargo run --release with the same --no-default-features/--features ... flags, or keep build/run flags consistent (or run the built binary directly).

Suggested change

	RUSTFLAGS="-Awarnings" cargo run --no-default-features --features postgres
	# MySQL build
	cargo build --release --features release
	RUSTFLAGS="-Awarnings" cargo run --features release
	RUSTFLAGS="-Awarnings" cargo run --release --no-default-features --features middleware,kms-aws,postgres
	# MySQL build
	cargo build --release --features release
	RUSTFLAGS="-Awarnings" cargo run --release --features release

[Copilot]

config.example.toml is described here as the “full, commented reference”, but the current config.example.toml in the repo is a short/outdated sample (e.g., it lacks [metrics], [redis], routing_config, etc.). This line should either point to a truly complete reference file (e.g., config/development.toml / config/docker-configuration.toml) or config.example.toml should be updated to match the sections documented on this page.

Suggested change

	A full, commented reference lives at [`config.example.toml`](../config.example.toml) at the repo root — copy and edit it for custom deployments.
	Use the deployment-specific TOML files listed above as the authoritative configuration reference for each environment. If you need a starting point for a custom deployment, you can also copy and adapt [`config.example.toml`](../config.example.toml) from the repo root.