misc: Add baddev tooling

I think this is the *wrong* way to build this, but it's perfectly legal
to have a feature branch with this committed that people can develop
against. We can always cherry-pick off those commits to merge them, and
we can update and rebase this commit over time when needed.

misc/make-baddev.sh

@@ -0,0 +1,11 @@
+#!/bin/bash
+# Make a new "baddev" branch, start on whatever branch you want to base it on.
+git checkout -B baddev # scary -B reset the branch
+make
+git add lang/parser/lexer.nn.go --force
+git add lang/parser/y.go --force
+git add lang/interpolate/parse.generated.go --force
+git add lang/core/generated_funcs.go --force
+git commit -m 'lang: Commit generated code'
+git push origin baddev --force
+echo 'run `make baddev` to build a binary!'