Add tools/gencommit.sh which will only generate the commithash SVG

This is useful so we aren't wasting cycles generating examples that
don't need to be generated and we just cut to the chase

Signed-off-by: Alek Ratzloff <alekratz@gmail.com>

tools/genexamples.sh

@@ -22,5 +22,4 @@ while read infile; do
 done
 
 # Additionally, create an SVG for the current commit hash
-echo "Generating examples/commithash.svg"
-python3 -m colorhash "$(git rev-parse HEAD)" --input-type hash --hash sha1 --output-type svg --out examples/commithash.svg
+tools/gencommit.sh