Add .tiltignore

.tiltignore specifies files for Tilt to ignore when it does automatic
rebuilds. Ignoring these common text files prevents unnecessary rebuilds.

Signed-off-by: Tayler Geiger <tayler@redhat.com>

Author: trgeiger

.tiltignore

@@ -0,0 +1,7 @@
+.md
+.txt
+.toml
+LICENSE
+Makefile
+.github
+.vscode