Add new decidim's worldwide :)

[xabier]

I recently discovered these 4:

• https://participation.lillemetropole.fr/

• http://burgos.decidimos.pt/

• https://dialogue-trianon.fr/

• https://participate.oidp.net/

[xabier]

PR waiting for review at #118

[andreslucena]

Already added them, closing this issue