Export plugins per category to markdown

Request to generate markdown of plugins per category, ex:

| Category | Category Description | Plugins in this category |
| --- | --- | --- | 
| Backup | Backup plugins | <a href="https://github.com/denolehov/obsidian-git">Obsidian Git</a>, <a href="https://github.com/ryanpcmcquen/obsidian-dropbox-backups">Aut-O-Backups</a> |