Add ABB120 demo suite and docs

kdl-wasm/web/src/grl/semantic/compileIo.ts

@@ -339,6 +339,9 @@ class IoStatementParser {
   }
 
   private matchKeyword(keyword: string): boolean {
+    if (this.isAtEnd()) {
+      return false;
+    }
     const token = this.peek();
     if ((token.kind === "keyword" || token.kind === "identifier") && token.raw === keyword) {
       this.advance();
@@ -348,6 +351,9 @@ class IoStatementParser {
   }
 
   private checkKeyword(keyword: string): boolean {
+    if (this.isAtEnd()) {
+      return false;
+    }
     const token = this.peek();
     return (token.kind === "keyword" || token.kind === "identifier") && token.raw === keyword;
   }