feat: improve skill quality scores across 4 skills

Ran skills through tessl evaluation tooling and applied targeted
improvements to structure, conciseness, and workflow clarity.

| Skill             | Before | After | Change |
|-------------------|--------|-------|--------|
| defuddle          |  100%  | 100%  |   --   |
| json-canvas       |   83%  | 100%  |  +17%  |
| obsidian-bases    |   83%  | 100%  |  +17%  |
| obsidian-cli      |   94%  | 100%  |   +6%  |
| obsidian-markdown |   71%  |  94%  |  +23%  |

Changes:
- Add structured workflows with validation steps
- Extract verbose reference tables to references/ files (progressive disclosure)
- Remove standard Markdown content Claude already knows (obsidian-markdown)
- Add troubleshooting section for common YAML/formula errors (obsidian-bases)
- Restructure plugin dev section into numbered test cycle (obsidian-cli)
- Condense redundant examples, keep one per pattern

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

skills/obsidian-markdown/references/PROPERTIES.md

@@ -0,0 +1,61 @@
+# Properties (Frontmatter) Reference
+
+Properties use YAML frontmatter at the start of a note:
+
+```yaml
+---
+title: My Note Title
+date: 2024-01-15
+tags:
+  - project
+  - important
+aliases:
+  - My Note
+  - Alternative Name
+cssclasses:
+  - custom-class
+status: in-progress
+rating: 4.5
+completed: false
+due: 2024-02-01T14:30:00
+---
+```
+
+## Property Types
+
+| Type | Example |
+|------|---------|
+| Text | `title: My Title` |
+| Number | `rating: 4.5` |
+| Checkbox | `completed: true` |
+| Date | `date: 2024-01-15` |
+| Date & Time | `due: 2024-01-15T14:30:00` |
+| List | `tags: [one, two]` or YAML list |
+| Links | `related: "[[Other Note]]"` |
+
+## Default Properties
+
+- `tags` - Note tags (searchable, shown in graph view)
+- `aliases` - Alternative names for the note (used in link suggestions)
+- `cssclasses` - CSS classes applied to the note in reading/editing view
+
+## Tags
+
+```markdown
+#tag
+#nested/tag
+#tag-with-dashes
+#tag_with_underscores
+```
+
+Tags can contain: letters (any language), numbers (not first character), underscores `_`, hyphens `-`, forward slashes `/` (for nesting).
+
+In frontmatter:
+
+```yaml
+---
+tags:
+  - tag1
+  - nested/tag2
+---
+```