DEVX-118: feat: enhance documentation-as-code with badges, version refs, Vale

- Fix badge system: clean .badges dir from orphan branch, add version
  verification, make badges job depend on release (avoids stale version
  badge race condition)
- Add check_doc_versions.py: lint tool that verifies docs version
  references match current __version__, with --fix for auto-update
- Integrate check_doc_versions into release process (auto-updates docs
  on every release commit)
- Add Vale prose linter integration: .vale.ini, custom styles for
  terminology and code block language, CI step, make target
- Fix stale version references in docs (0.27.0 → 0.33.4)
- Fix e.g. → for example in docs (Google.Latin Vale rule)
- Add CI steps for check_doc_versions and Vale to quality workflow
- Add make targets: devx-check-doc-versions, devx-vale

Generated with [Devin](https://devin.ai)

Co-Authored-By: Devin <158243242+devin-ai-integration[bot]@users.noreply.github.com>

.vale/styles/Readability/AutomatedReadability.yml

@@ -0,0 +1,8 @@
+extends: metric
+message: "Try to keep the Automated Readability Index (%s) below 8."
+link: https://en.wikipedia.org/wiki/Automated_readability_index
+
+formula: |
+  (4.71 * (characters / words)) + (0.5 * (words / sentences)) - 21.43
+
+condition: "> 8"

.vale/styles/Readability/ColemanLiau.yml

@@ -0,0 +1,8 @@
+extends: metric
+message: "Try to keep the Coleman–Liau Index grade (%s) below 9."
+link: https://en.wikipedia.org/wiki/Coleman%E2%80%93Liau_index
+
+formula: |
+  (0.0588 * (characters / words) * 100) - (0.296 * (sentences / words) * 100) - 15.8
+
+condition: "> 9"

.vale/styles/Readability/FleschKincaid.yml

@@ -0,0 +1,8 @@
+extends: metric
+message: "Try to keep the Flesch–Kincaid grade level (%s) below 8."
+link: https://en.wikipedia.org/wiki/Flesch%E2%80%93Kincaid_readability_tests
+
+formula: |
+  (0.39 * (words / sentences)) + (11.8 * (syllables / words)) - 15.59
+
+condition: "> 8"

.vale/styles/Readability/FleschReadingEase.yml

@@ -0,0 +1,8 @@
+extends: metric
+message: "Try to keep the Flesch reading ease score (%s) above 70."
+link: https://en.wikipedia.org/wiki/Flesch%E2%80%93Kincaid_readability_tests
+
+formula: |
+  206.835 - (1.015 * (words / sentences)) - (84.6 * (syllables / words))
+
+condition: "< 70"

.vale/styles/Readability/GunningFog.yml

@@ -0,0 +1,8 @@
+extends: metric
+message: "Try to keep the Gunning-Fog index (%s) below 10."
+link: https://en.wikipedia.org/wiki/Gunning_fog_index
+
+formula: |
+  0.4 * ((words / sentences) + 100 * (complex_words / words))
+
+condition: "> 10"

.vale/styles/Readability/LIX.yml

@@ -0,0 +1,17 @@
+extends: metric
+message: "Try to keep the LIX score (%s) below 35."
+
+link: https://en.wikipedia.org/wiki/Lix_(readability_test)
+# Very Easy: 20 - 25
+#
+# Easy: 30 - 35
+#
+# Medium: 40 - 45
+#
+# Difficult: 50 - 55
+#
+# Very Difficult: 60+
+formula: |
+  (words / sentences) + ((long_words * 100) / words)
+
+condition: "> 35"

.vale/styles/Readability/SMOG.yml

@@ -0,0 +1,8 @@
+extends: metric
+message: "Try to keep the SMOG grade (%s) below 10."
+link: https://en.wikipedia.org/wiki/SMOG
+
+formula: |
+  1.0430 * math.sqrt((polysyllabic_words * 30.0) / sentences) + 3.1291
+
+condition: "> 10"

.vale/styles/Readability/meta.json

@@ -0,0 +1,4 @@
+{
+  "feed": "https://github.com/errata-ai/Readability/releases.atom",
+  "vale_version": ">=2.13.0"
+}