zess: add pre-commit hook to check commit message

.githooks/commit-msg

@@ -0,0 +1,19 @@
+#!/bin/sh
+
+commit_message=$(<"$1")
+
+if ! [[ $commit_message =~ ^(vingo:|vinscant:|vinvoor:|zess:) ]]; then
+    echo "Error: commit message should start with vingo:|vinscant:|vinvoor:|zess: depending on which subproject you are working on."
+    exit 1
+fi
+
+if ! [[ $commit_message =~ ^.*:\ [a-z].* ]]; then
+    echo "Error: first letter after project specifier should be lower case
+Example:
+    vingo: add cheese
+           ^
+           | this one"
+    exit 1
+fi
+
+exit 0