Snipets tooling update

- update README
- generate-md.py: ignore trailing newlines when complaining about diffs
- all langs: add more dependencies to templates
- all langs: support @hide-start and @hide-end for multi-line hiding
- go: also allow one-line imports
- java: allow declarations other than `main` method
- python, typescript: implement `unshorten` for implicit imports and
  client initialization
- python: add mypy config as `datasets` lacks type py.typed
- python: hide `# mypy:` annotations
- typescript: add tsconfig that allows top-level `await`s
- typescript: depend on @types/node to fix `import ... from "crypto"`

automation/snippets/lib/languages/go.py

@@ -92,7 +92,12 @@ class LanguageGo(Language):
 
     RE_RENDERED = re.compile(
         r"""
-        (?P<imports> (?:import\s*\([^)]+\)\n|\n)* )
+        (?P<imports>
+            (?: import\s*\([^)]+\)\n
+              | import\s+"[^"]+"\n
+              | \n
+            )*
+        )
         (?P<body> .* )
         $
         """,