feat: support vale flags

[chanchiwai-ray]

Applicable spec:

Overview

Support vale-flags input for docs.yaml workflow, and default to --glob=*.md.

Rationale

The files input parameter in action-vale does not support globing, we need to use vale_flags to do globing. This feature may be useful in monorepo setup where you have some markdown files also in the charm directory. Using this flag (e.g. --glob=*.md) can avoid running vale on python files.

Workflow Changes

Checklist

• The contributing guide was applied
• The PR is tagged with appropriate label (urgent, trivial, complex)
• The changelog is updated with user-relevant changes in the format of keep a changelog v1.1.0

[chanchiwai-ray]

An example showing that glob does not work in the CI is https://github.com/canonical/postfix-relay-operators/actions/runs/21898626334/job/63220750701. Note that although vale passed, but it ran on no files. You can cross check the output using make vale or vale ./**/*.md (in a e.g. bash shell), there are errors:

$ make vale

--- Syncing Vale styles... ---
Syncing pfe-vale [1/1] ███████████████████████████████████████████████ 100% | 0s
 SUCCESS  Synced 1 package(s) to '/home/raychan/Scratchspace/postfix-relay-operators/.vale/styles'.
--- Running Vale checks on "./**/*.md"... ---

 postfix-relay-configurator-operator/CONTRIBUTING.md
 7:115  error  The word 'configurator' seems   Canonical.000-US-spellcheck
               to be misspelled.

✖ 1 error, 0 warnings and 0 suggestions in 4 files.
make: *** [Makefile.docs:56: vale] Error 1

[chanchiwai-ray]

cc @erinecon

[erinecon]

LGTM

[github-actions]

Test results for commit 0854108

Test coverage for 0854108

Name           Stmts   Miss Branch BrPart  Cover   Missing
----------------------------------------------------------
src/charm.py       8      8      0      0     0%   8-25
----------------------------------------------------------
TOTAL              8      8      0      0     0%

Static code analysis report

Run started:2026-03-18 17:12:23.691064+00:00

Test results:
  No issues identified.

Code scanned:
  Total lines of code: 56
  Total lines skipped (#nosec): 0
  Total potential issues skipped due to specifically being disabled (e.g., #nosec BXXX): 0

Run metrics:
  Total issues (by severity):
  	Undefined: 0
  	Low: 0
  	Medium: 0
  	High: 0
  Total issues (by confidence):
  	Undefined: 0
  	Low: 0
  	Medium: 0
  	High: 0
Files skipped (0):

[github-actions]

Test results for commit 0854108

Test coverage for 0854108

Name           Stmts   Miss Branch BrPart  Cover   Missing
----------------------------------------------------------
src/charm.py       8      8      0      0     0%   8-25
----------------------------------------------------------
TOTAL              8      8      0      0     0%

Static code analysis report

Run started:2026-03-18 17:12:21.857569+00:00

Test results:
  No issues identified.

Code scanned:
  Total lines of code: 56
  Total lines skipped (#nosec): 0
  Total potential issues skipped due to specifically being disabled (e.g., #nosec BXXX): 0

Run metrics:
  Total issues (by severity):
  	Undefined: 0
  	Low: 0
  	Medium: 0
  	High: 0
  Total issues (by confidence):
  	Undefined: 0
  	Low: 0
  	Medium: 0
  	High: 0
Files skipped (0):

[github-actions]

Test results for commit 0854108

Test coverage for 0854108

Name           Stmts   Miss Branch BrPart  Cover   Missing
----------------------------------------------------------
src/charm.py       8      8      0      0     0%   8-25
----------------------------------------------------------
TOTAL              8      8      0      0     0%

Static code analysis report

Run started:2026-03-18 17:12:20.067671+00:00

Test results:
  No issues identified.

Code scanned:
  Total lines of code: 56
  Total lines skipped (#nosec): 0
  Total potential issues skipped due to specifically being disabled (e.g., #nosec BXXX): 0

Run metrics:
  Total issues (by severity):
  	Undefined: 0
  	Low: 0
  	Medium: 0
  	High: 0
  Total issues (by confidence):
  	Undefined: 0
  	Low: 0
  	Medium: 0
  	High: 0
Files skipped (0):