docs: track aitools rename — 'experimental aitools install' → 'aitools install'

Mirrors the CLI change in databricks/cli#4917 which promotes the
aitools skills-management surface (install/update/uninstall/list/
version/skills) from `databricks experimental aitools` to top-level
`databricks aitools`.

Updates 3 install-command references:
- README.md
- skills/databricks-jobs/SKILL.md
- skills/databricks-pipelines/SKILL.md

The 37 `databricks experimental aitools tools …` references in
skills/databricks-core/, skills/databricks-apps/, and elsewhere are
intentionally left as-is — that subtree (query, discover-schema,
get-default-warehouse, statement) still has "no stability guarantees"
per its own help text and is NOT being promoted to the top level in
#4917. It stays under `experimental aitools tools`.

Co-authored-by: Isaac

Author: jamesbroadhead

README.md

@@ -5,7 +5,7 @@ Skills for AI coding assistants (Claude Code, Cursor, etc.) that provide Databri
 ## Installation
 
 ```bash
-databricks experimental aitools install
+databricks aitools install
 ```
 
 This auto-detects your coding agent(s) and installs the stable skills to the

skills/databricks-jobs/SKILL.md

@@ -53,7 +53,7 @@ Verify: `databricks -v`
 Read the `databricks-core` skill for CLI basics, authentication, and deployment workflow.
 Read the `databricks-jobs` skill for job-specific guidance.
 
-If skills are not available, install them: `databricks experimental aitools install`
+If skills are not available, install them: `databricks aitools install`
 ```
 
 ## Project Structure

skills/databricks-pipelines/SKILL.md

@@ -202,7 +202,7 @@ Verify: `databricks -v`
 Read the `databricks-core` skill for CLI basics, authentication, and deployment workflow.
 Read the `databricks-pipelines` skill for pipeline-specific guidance.
 
-If skills are not available, install them: `databricks experimental aitools install`
+If skills are not available, install them: `databricks aitools install`
 ```
 
 ## Pipeline Structure