fix: resolve markdownlint errors across documentation (#1571)

- Add language specifiers to fenced code blocks (bash, text)
- Fix whitespace issues around code fences
- Disable MD036 (emphasis as heading) for intentional warning text
- Disable MD060 (table column style) for existing table formats

Co-authored-by: Claude Opus 4.5 <noreply@anthropic.com>

.markdownlint-cli2.jsonc

@@ -19,7 +19,9 @@
     },
     "MD050": {
       "style": "asterisk"
-    }
+    },
+    "MD036": false,
+    "MD060": false
   },
   "ignores": [
     ".genreleases/"