chore: Migrate docs from EDoc to Markdown

[Benjamin-Philip]

What issue does this PR close?

Closes #103.

What's Changed

Inline documentation has been migrated to markdown.

Erlang/OTP, Rebar3 and rebar3_ex_doc have all been updated to the latest
stable version in order to use the new markdown support.

[github-actions]

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[Copilot]

Pull request overview

This PR migrates inline Erlang module/function/type documentation from EDoc markup to Erlang/OTP’s Markdown-based documentation system, and updates the build/tooling versions required to support it.

Changes:

• Converted arrow_array inline docs to -moduledoc/-doc Markdown strings.
• Bumped rebar3_ex_doc to a newer version to support Markdown doc generation.
• Updated GitHub Actions workflows to build/test/docs against newer Erlang/OTP and Rebar3 versions.

Reviewed changes

Copilot reviewed 3 out of 4 changed files in this pull request and generated 7 comments.

File	Description
src/arrow_array.erl	Migrates EDoc to Markdown using -moduledoc/-doc and updates doc formatting/content.
rebar.config	Updates rebar3_ex_doc plugin version to support Markdown docs.
.github/workflows/erlang.yml	Bumps OTP/Rebar3 versions for CI jobs.
.github/workflows/docs.yml	Bumps OTP/Rebar3 versions for doc generation workflow.

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[Copilot]

Pull request overview

Copilot reviewed 19 out of 20 changed files in this pull request and generated 20 comments.

Comments suppressed due to low confidence (2)

src/arrow_array.erl:160

• #array.data is always set to a buffer or nested array (see src/arrow_array.hrl), so the data/1 typespec including undefined is inconsistent with the record definition.

-doc "Returns the data of an array.".
-spec data(Array :: array()) -> Data :: arrow_buffer:buffer() | array() | undefined.
data(Array) ->
    Array#array.data.

src/arrow_array.erl:178

• Spelling: “ommitted” should be “omitted” in the to_arrow/1 documentation.

In case an array doesn't have any of the following buffers, it is ommitted.

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[Benjamin-Philip]

@kou, I'll rebase on main once you merge #108. Hopefully we should have the CI
working again (and the docs re-deployed for this PR instead of #108) after that.

[Copilot]

Copilot was unable to review this pull request because the user who requested the review has reached their quota limit.

[Benjamin-Philip]

Rebased onto main. This is a PR where further Copilot reviews would have been helpful. It's been fairly good at catching silly spelling and grammar mistakes.

Anyway, you can have a look.

[kou]

+1