* Update extensions.md
Added in Kitronik packages as all were missing.
* Update extensions.md
fixed misplaced urls
* Update extensions.md
changed URLs to pkg format, after actually checking them in the correct place.
* add PiSupply
Add PiSupply as approved organisation.
They have acknowledged caveats to submit theirown PRs and update the gallery. They have also agreed to tag beta packages
* Update targetconfig.json