Log Message:
editors/tp-note: update to 1.25.1

Bugfix release: this release fixes a minor regression introduced with v1.25.0

The commit:

    d79a706  Centralize HTML stream tagging code

did not detect the empty clipboard properly and therefor the template
`from_clipboard` was applied in cases where `from_dir` were the right choice.
Fixed.

This release completes the new feature introduced in v1.25.0:

When you copy a chapter with its heading in your browser, Tp-Note will place
the heading in the `title:` field of the new note's YAML header.

Technical details: A new filter `html_heading` used in the
`from_clipboard_content` template extracts the first HTML heading in the HTML
clipboard.