docs: create docs about migration to Froggit

Based on these issues:

• https://gitlab.com/froggit/infra/-/issues/356
• https://gitlab.com/froggit/infra/-/issues/366
• https://gitlab.com/froggit/infra/-/issues/206

added Doing label

assigned to @arthur.boudreault

changed the description

created branch 94-docs-create-docs-about-migration-to-froggit to address this issue

mentioned in merge request !67 (merged)

added Need Review + 1 deleted label and removed Doing label

mentioned in commit 960f8aca

closed with merge request !67 (merged)