Add pre-commit hooks. Drop the shebang from z-ps-twtty-7.sh.

.pre-commit-config.yaml

@@ -0,0 +1,19 @@
+---
+repos:
+  - repo: https://github.com/pre-commit/pre-commit-hooks
+    rev: v4.5.0
+    hooks:
+      - id: check-added-large-files
+        args: [ '--maxkb=64' ]
+      - id: check-merge-conflict
+      - id: check-shebang-scripts-are-executable
+      - id: check-symlinks
+      - id: check-toml
+      - id: check-yaml
+      - id: detect-private-key
+      - id: end-of-file-fixer
+      - id: fix-byte-order-marker
+      - id: fix-encoding-pragma
+      - id: mixed-line-ending
+        args: [ '--fix=lf' ]
+      - id: trailing-whitespace