Allow triggering build-mkdocs-website.yml manually

Author: LouisCAD

.github/workflows/build-mkdocs-website.yml

@@ -8,6 +8,7 @@ on:
       - 'mkdocs.yml'
       - 'CHANGELOG.md'
       # Any additional files/dirs that take part in updating the website must be added here.
+  workflow_dispatch:
 jobs:
   deploy:
     runs-on: ubuntu-latest