Modularize UI, make it a bit more Lisp independent

src/languages/lisp/index.ts

@@ -0,0 +1,22 @@
+export { parseDocument, programOf } from './parser';
+export type {
+  ConcreteSyntaxResult,
+  ParseDocumentResult,
+  PartialConcreteSyntax,
+  ValidConcreteSyntax,
+  PartialExpr,
+  PartialList,
+  PartialListItem,
+} from './parser';
+export type { FoundSyntax, ParseError } from './parse_errors';
+export type {
+  ConcreteError,
+  ConcreteErrorNode,
+  ConcreteInfo,
+  DelimiterToken,
+  Expr,
+  List,
+  ListItem,
+  Program,
+} from './syntax';
+export { Expr as LispExpr } from './syntax';