chore: Set up development environment

Add the civet and typescript compilers, implement a build step,
  provide examples of using from es6, script, and command line.
  Of course, there is no actual behavior produced; convert always produces
  'foo' at the moment.

src/example.civet

@@ -0,0 +1,2 @@
+{convert} from ./index.js
+console.log convert 'bar'

src/index.civet

@@ -0,0 +1,14 @@
+type Tree = {[key:string]: string | Tree}
+
+export function tree97(vrml1: string): Tree
+   {converted: 'foo'}
+
+function render(t: string | Tree): string
+   if typeof t is 'string'
+      return t
+   if result := t.converted
+      render result
+   else '<Conversion failed>'
+
+export function convert(vrml1: string): string
+   render tree97 vrml1