perserve newlines in description and changelogs
Many app descriptions use newlines/linefeeds to do some very basic layout. This worked using the mediawiki syntax from the old website. Changelogs only have plain text for formatting. When parsing descriptions and changelogs from index-v1.json, all \n should be converted to <br />. I think currently, only \n\n are being converted. See this page for an example:
https://fdroid.gitlab.io/fdroid-website/packages/org.sufficientlysecure.keychain/