plan: drop invalid enabled: config keys, fix spelling and message case

Agent-Logs-Url: https://github.com/jeduden/mdsmith/sessions/9c7474b1-6cbb-474a-a72d-9f8390848936

Co-authored-by: jeduden <1117699+jeduden@users.noreply.github.com>

Author: Copilot

docs/background/markdown-linters.md

@@ -149,7 +149,7 @@ the same `.md` files.
   and inline metadata (`key:: value`)
 - No built-in linter — community plugins (e.g. [Linter
   plugin][obsidian-linter]) add YAML front matter fixes,
-  heading normalisation, and whitespace rules
+  heading normalization, and whitespace rules
 - Files are plain `.md` on disk and are committed to Git
   like any other source; CI can run mdsmith over the vault
 

plan/124_no-space-in-code-spans.md

@@ -46,8 +46,7 @@ independent of fenced-block policy.
 
 ```yaml
 rules:
-  no-space-in-code-spans:
-    enabled: true
+  no-space-in-code-spans: true
 ```
 
 Category: `whitespace`. Disabled by default (opt-in).

plan/125_no-space-in-link-text.md

@@ -56,7 +56,6 @@ because the text portion is still visible.
 ```yaml
 rules:
   no-space-in-link-text:
-    enabled: true
     check-images: true
 ```
 

plan/127_single-h1.md

@@ -53,7 +53,6 @@ it only caps the count when one or more are present.
 ```yaml
 rules:
   single-h1:
-    enabled: true
     front-matter-title: title
 ```
 
@@ -97,7 +96,7 @@ applied in that case — emit the diagnostic only.
 
 ```text
 extra H1 heading; only one H1 is allowed per file
-H1 heading conflicts with front-matter title
+h1 heading conflicts with front-matter title
 ```
 
 ## Tasks

plan/128_no-undefined-reference-labels.md

@@ -96,7 +96,6 @@ A `shortcut` setting (`always` | `collapsed-only` |
 ```yaml
 rules:
   no-undefined-reference-labels:
-    enabled: true
     shortcut: heuristic
     placeholders: []
 ```

plan/129_no-unused-link-definitions.md

@@ -79,7 +79,6 @@ before comparison.
 ```yaml
 rules:
   no-unused-link-definitions:
-    enabled: true
     ignored-labels: []
 ```