Make writeDocs() with Runnable public (#939)

smithy-typescript-codegen/src/main/java/software/amazon/smithy/typescript/codegen/TypeScriptWriter.java

@@ -147,7 +147,7 @@ public TypeScriptWriter addRelativeImport(String name, String as, Path from) {
      * @param runnable Runnable that handles actually writing docs with the writer.
      * @return Returns the writer.
      */
-    TypeScriptWriter writeDocs(Runnable runnable) {
+    public TypeScriptWriter writeDocs(Runnable runnable) {
         pushState("docs");
         write("/**");
         setNewlinePrefix(" * ");