BFG is deprecated and shouldn't be recommended

doc/topics/git/lfs/migrate_to_git_lfs.md

@@ -7,6 +7,11 @@ description: "How to migrate an existing Git repository to Git LFS with BFG."
 
 # Migrate a Git repository into Git LFS with BFG
 
+WARNING:
+The following documentation is deprecated. We recommend using
+[`git lfs migrate`](https://github.com/git-lfs/git-lfs/blob/main/docs/man/git-lfs-migrate.1.ronn)
+instead of the method documented below.
+
 Using Git LFS can help you to reduce the size of your Git
 repository and improve its performance.
 

doc/topics/git/numerous_undo_possibilities_in_git/index.md

@@ -388,7 +388,6 @@ git filter-branch --tree-filter 'rm filename' HEAD
 
 The `git filter-branch` command might be slow on large repositories.
 Tools are available to execute Git commands more quickly.
-An alternative is the open source community-maintained tool [BFG](https://rtyley.github.io/bfg-repo-cleaner/).
 These tools are faster because they do not provide the same
 feature set as `git filter-branch` does, but focus on specific use cases.