docs(README): fix usage example for standalone usage to use composeCreateOrUpdateTextFile() (#301)

Co-authored-by: wolfy1339 <[email protected]>

Author: klvenky

README.md

@@ -135,7 +135,7 @@ const { updated, deleted, data } = await octokit.createOrUpdateTextFile({
 ```js
 const octokit = new Octokit({ auth: "secret123" });
 
-await { updated, deleted, data } = await createOrUpdateTextFile(octokit, {
+await { updated, deleted, data } = await composeCreateOrUpdateTextFile(octokit, {
   owner: "octocat",
   repo: "hello-world",
   path: "test.txt",