chore: lock in nph version and add pre-commit hook (#2938)

scripts/git_pre_commit_format.sh

@@ -0,0 +1,16 @@
+#!/bin/sh
+
+echo "Running pre-commit hook"
+
+# Regexp for grep to only choose some file extensions for formatting
+exts="\.\(nim\|nims\)$"
+
+# Build nph lazily
+make build-nph || (1>&2 echo "failed to build nph. Pre-commit formatting will not be done."; exit 0)
+
+# Format staged files
+git diff --cached --name-only --diff-filter=ACMR | grep "$exts" | while read file; do
+  echo "Formatting $file"
+  make nph/"$file"
+  git add "$file"
+done