tools: capitalize sentences

This adds the `capitalized-comments` eslint rule to verify that
actual sentences use capital letters as starting letters. It ignores
special words and all lines below 62 characters.

PR-URL: https://github.com/nodejs/node/pull/24808
Reviewed-By: Sam Ruby <rubys@intertwingly.net>
Reviewed-By: Trivikram Kamat <trivikr.dev@gmail.com>
Reviewed-By: Ujjwal Sharma <usharma1998@gmail.com>
Reviewed-By: Sakthipriyan Vairamani <thechargingvolcano@gmail.com>

lib/buffer.js

@@ -916,7 +916,7 @@ Buffer.prototype.write = function write(string, offset, length, encoding) {
     if (string.length > 0 && (length < 0 || offset < 0))
       throw new ERR_BUFFER_OUT_OF_BOUNDS();
   } else {
-    // if someone is still calling the obsolete form of write(), tell them.
+    // If someone is still calling the obsolete form of write(), tell them.
     // we don't want eg buf.write("foo", "utf8", 10) to silently turn into
     // buf.write("foo", "utf8"), so we can't ignore extra args
     throw new ERR_NO_LONGER_SUPPORTED(