Suggest running yarn lint --fix (#23413)

Summary:
This PR expands the code analysis script to allow for customizing the GitHub Review left by analysis-bot whenever it finds code-level issues.

Some, but not all, `eslint` errors are fixable by running `yarn lint --fix`. When the `eslint` converter finds warnings or errors, the bot will suggest running the command as part of the review.

The script could be adjusted to only suggest this when `eslint` returns a non-zero `fixableErrorCount` or `fixableWarningCount`, but I think this is a good first step to get people to unblock themselves when they see this type of review from the bot.

I've also excluded `bots/` and `scripts/` from eslint as these have several `eslint` errors that need to be addressed. These directories do not contain core RN code, so they can be excluded for now.

[GENERAL] [Changed] - analysis-bot will suggest fixing eslint warnings on code reviews
Pull Request resolved: #23413

Differential Revision: D14065757

Pulled By: cpojer

fbshipit-source-id: cc588643f7ddb3c4631d89c26b799f7a7244e616

.eslintignore

@@ -7,4 +7,4 @@ Libraries/Renderer/*
 pr-inactivity-bookmarklet.js
 question-bookmarklet.js
 flow/
-danger/
+bots/node_modules

scripts/circleci/code-analysis-bot.js

@@ -30,6 +30,13 @@ function push(arr, key, value) {
   arr[key].push(value);
 }
 
+const converterSummary = {
+  eslint:
+    '`eslint` found some issues. Run `yarn lint --fix` to automatically fix problems.',
+  flow: '`flow` found some issues.',
+  shellcheck: '`shellcheck` found some issues.',
+};
+
 /**
  * There is unfortunately no standard format to report an error, so we have
  * to write a specific converter for each tool we want to support.
@@ -250,7 +257,7 @@ function main(messages, owner, repo, number) {
       let body = '**Code analysis results:**\n\n';
       const uniqueconvertersUsed = [...new Set(convertersUsed)];
       uniqueconvertersUsed.forEach(converter => {
-        body += '* `' + converter + '` found some issues.\n';
+        body += '* ' + converterSummary[converter] + '\n';
       });
 
       sendReview(owner, repo, number, sha, body, comments);