Make LinkedMusic independant of forestry

[zhannaklimanova]

• [x] Use Jekyll to deploy website so an updated _site folder is generated
• [x] Remove all Jekyll .md files and replace with .html versions
• [x] Add broken link checker to Github actions
• [x] Fix all broken links between pages
• [x] Ensure that broken link checker is passing with most important links between pages
• [x] Manually double check that the main links are leading to expected locations
• [x] Prettify the .html files so they can be edited easily in the future
• [x] Remove any unnecessary/deprecated scripts/folders/files from deforested website
• [x] Push all changes to deforested branch
• [x] Change the Github settings to deploy from deforested branch for testing purposes
• [x] Update README instructions
• [x] Issue pull request for merge into master
• [x] Resolve any outstanding issues or requested changes from PR