build: remove unsupported tags from appdata.xml (#1427)(PR #1428)
build: remove unsupported tags from appdata.xml (#1427)(PR #1428)

* remove <code> tags from appdata.xml because flatpak doesn't like it
* appdata.xml: remove <a> tag because flatpak doesn't like it
NeoSpb/jadx,skylot/jadx,jpstotz/jadx