docs: document rc --force parity behavior

README.md

@@ -42,7 +42,7 @@ Implemented commands:
 - `cd [CASTLE]`
 - `open [CASTLE]`
 - `generate PATH`
-- `rc [CASTLE]`
+- `rc [--force] [CASTLE]`
 - `version`
 
 ### rc behavior
@@ -50,6 +50,7 @@ Implemented commands:
 - Runs executable scripts in `<castle>/.homesick.d/` in lexicographic order.
 - Executes scripts with the castle root as the current working directory.
 - Forwards script stdout/stderr to command output.
+- If `<castle>/.homesickrc` exists, `--force` is required before legacy Ruby compatibility hooks are run.
 - If `<castle>/.homesickrc` exists and `<castle>/.homesick.d/parity.rb` does not, generates `parity.rb` before execution.
 - Never overwrites an existing `parity.rb` wrapper.
 
@@ -75,7 +76,7 @@ Command parity:
 Historical flag/behavior parity:
 
 - [x] `pull --all`
-- [ ] `rc --force`
+- [x] `rc --force`
 - [ ] Evaluate whether global `pretend`/`quiet` modes should be restored
 
 ## Behavior Suite