add forbid-submodules hook

Author: asottile

.pre-commit-hooks.yaml

@@ -156,6 +156,12 @@
     language: python
     entry: forbid-new-submodules
     types: [directory]
+-   id: forbid-submodules
+    name: forbid submodules
+    description: forbids any submodules in the repository
+    language: fail
+    entry: 'submodules are not allowed in this repository:'
+    types: [directory]
 -   id: mixed-line-ending
     name: mixed line ending
     description: replaces or checks mixed line ending.

README.md

@@ -133,6 +133,12 @@ The following arguments are available:
 #### `forbid-new-submodules`
 Prevent addition of new git submodules.
 
+This is intended as a helper to migrate away from submodules.  If you want to
+ban them entirely use `forbid-submodules`
+
+#### `forbid-submodules`
+forbids any submodules in the repository.
+
 #### `mixed-line-ending`
 Replaces or checks mixed line ending.
   - `--fix={auto,crlf,lf,no}`