Restore merged-PR context for site publishing (#58)

## Summary
- remove push trigger on main
- restore pull_request.closed in Process-PSModule triggers

## Why
Publish-Site in Process-PSModule is computed from merged PR context
(pull_request + closed + merged). Running only on push to main caused
Publish-Site to be skipped, so deployed Pages could drift from the
latest merged build artifact.

---------

Co-authored-by: Copilot App <223556219+Copilot@users.noreply.github.com>

Author: MariusStorhaug

README.md

@@ -53,8 +53,7 @@ To find examples of each of the commands you can use Get-Help -Examples 'Command
 
 ## Documentation
 
-Link to further documentation if available, or describe where in the repository users can find more detailed documentation about
-the module's functions and features.
+Function documentation is published to the project site under the `Functions` section and is generated from the module source.
 
 ## Contributing