Fix crowdin badge display in CONTRIBUTING.md (#12273)
Fix crowdin badge display in CONTRIBUTING.md (#12273)

* Fix crowdin badge display in CONTRIBUTING.md

The Crowdin localization badge in `CONTRIBUTING.md` appeared to have the wrong markup around it. This manifested in some extra brackets and an unformatted `crowdin` string.

* Make Crowdin badge a link to the Mastodon project

danhunsaker/mastodon,theoria24/mastodon,tootsuite/mastodon,pinfort/mastodon,masto-donte-com-br/mastodon,kazh98/social.arnip.org,glitch-soc/mastodon,imas/mastodon,maa123/mastodon,musashino205/mastodon,Nyoho/mastodon,yi0713/mastodon,cobodo/mastodon,rainyday/mastodon,pinfort/mastodon,primenumber/mastodon,Kirishima21/mastodon,yukimochi/mastodon,lindwurm/mastodon,tri-star/mastodon,Ryanaka/mastodon,abcang/mastodon,theoria24/mastodon,cobodo/mastodon,Kirishima21/mastodon,theoria24/mastodon,abcang/mastodon,ikuradon/mastodon,maa123/mastodon,koba-lab/mastodon,tootcafe/mastodon,rainyday/mastodon,imas/mastodon,yukimochi/mastodon,kazh98/social.arnip.org,h3zjp/mastodon,Nyoho/mastodon,tootsuite/mastodon,abcang/mastodon,dunn/mastodon,kirakiratter/mastodon,musashino205/mastodon,h3zjp/mastodon,yukimochi/mastodon,abcang/mastodon,ikuradon/mastodon,Nyoho/mastodon,im-in-space/mastodon,koba-lab/mastodon,gol-cha/mastodon,gol-cha/mastodon,tootcafe/mastodon,imas/mastodon,MitarashiDango/mastodon,danhunsaker/mastodon,theoria24/mastodon,yukimochi/mastodon,MitarashiDango/mastodon,Ryanaka/mastodon,primenumber/mastodon,h3zjp/mastodon,kirakiratter/mastodon,Ryanaka/mastodon,ykzts/mastodon,cobodo/mastodon,dunn/mastodon,Ryanaka/mastodon,tootcafe/mastodon,rainyday/mastodon,MitarashiDango/mastodon,kirakiratter/mastodon,danhunsaker/mastodon,lindwurm/mastodon,dunn/mastodon,koba-lab/mastodon,tootcafe/mastodon,Nyoho/mastodon,maa123/mastodon,glitch-soc/mastodon,Kirishima21/mastodon,ikuradon/mastodon,dunn/mastodon,danhunsaker/mastodon,lynlynlynx/mastodon,tootsuite/mastodon,lindwurm/mastodon,koba-lab/mastodon,yi0713/mastodon,yi0713/mastodon,pinfort/mastodon,kazh98/social.arnip.org,maa123/mastodon,primenumber/mastodon,lynlynlynx/mastodon,glitch-soc/mastodon,tri-star/mastodon,masto-donte-com-br/mastodon,MitarashiDango/mastodon,kazh98/social.arnip.org,h3zjp/mastodon,ykzts/mastodon,lynlynlynx/mastodon,im-in-space/mastodon,im-in-space/mastodon,Kirishima21/mastodon,cobodo/mastodon,lynlynlynx/mastodon,im-in-space/mastodon,lindwurm/mastodon,musashino205/mastodon,rainyday/mastodon,ikuradon/mastodon,tri-star/mastodon,tootsuite/mastodon,musashino205/mastodon,imas/mastodon,primenumber/mastodon,masto-donte-com-br/mastodon,yi0713/mastodon,kirakiratter/mastodon,pinfort/mastodon,masto-donte-com-br/mastodon,tri-star/mastodon,gol-cha/mastodon,ykzts/mastodon,gol-cha/mastodon,ykzts/mastodon,glitch-soc/mastodon