feat: install moo and use in toy example (#2)

I failed to find a satisfactory way to compile and import moo.js with
  fixed specifiers, so finally I just gave up and patched the distributed
  moo code to be an es6 module. Very ugly but it works.

Resolves #1.

Reviewed-on: #2
Co-authored-by: Glen Whitney <glen@studioinfinity.org>
Co-committed-by: Glen Whitney <glen@studioinfinity.org>

src/example.civet

@@ -1,2 +1,2 @@
 {convert} from ./index.js
-console.log convert 'bar'
+console.log convert 'while (10) cows\nmoo'

src/index.civet

@@ -1,14 +1,37 @@
+moo from ../deps/moo.js
+
 type Tree = {[key:string]: string | Tree}
 
+lexer := moo.compile
+   WS:      /[ \t]+/
+   comment: /\/\/.*?$/
+   number:  /0|[1-9][0-9]*/
+   string:  /"(?:\\["\\]|[^\n"\\])*"/
+   lparen:  '('
+   rparen:  ')'
+   keyword: 'while if else moo cows'.split(' ')
+   NL:
+      match: /\n/
+      lineBreaks: true
+
 export function tree97(vrml1: string): Tree
-   {converted: 'foo'}
+   tree: Tree := {}
+   for tok, index of lexer.reset vrml1
+      if tok.type then tree[`${index}`] = {tok.type, tok.value}
+   tree
 
 function render(t: string | Tree): string
    if typeof t is 'string'
       return t
-   if result := t.converted
-      render result
-   else '<Conversion failed>'
+   result .= ''
+   for item of Object.values t
+      if typeof item is 'string' then result += item + ' '
+      else switch item.type
+         'WS' // ignore
+         'NL'
+            result += "\n"
+         else result += render(item.type) + ' '
+   result
 
 export function convert(vrml1: string): string
    render tree97 vrml1