Failing Silently

This took a minute to figure out because even `-d` had nothing to say, but I had a few issues using this tool.

1) It uses `isURI` and thus cannot load files from the local system. I'm sure this has something to do with what I later discovered is Cheerio running an automation on the web form instead. The SlackAPI lets you list, but not write emoji. The error it gives around this is pretty confusing though.

2) There is no error or explanation on why one portion of the tool has access to a private Github org or repo, but another part does not. As I discovered, the CLI tool can get the `.yaml` file because my Terminal is authenticated, but Cheerio is injecting private, yet valid URIs into a page that does not have access but does not stick around to wait for errors in uploading, so it fails silently.

Just FYI. I realize this is 2 issues in one and I'm going to script a workaround using a public Github resources mirror, but I just wanted to share with you some error reporting issues and documentation upgrades you could make.

Oh, also, the https://emojipacks.com/ project can certainly provide copyright-protected content without getting sued because who cares, but *_selling_* that copyright-protected content is definitely going above and beyond a Cease and Desist letter and straight into sued for damages territory. I'd recommend you stop accepting payment for copyright-protected content you don't own immediately and pretend that never happened.

Cheers!

The report concerns the CLI's local-file handling, SlackAPI emoji behavior, Cheerio web-form uploads, and GitHub authentication; no source files or tests are named. Start by reproducing the silent-failure cases and tracing their error paths, then verify that failures are surfaced and the authentication and file-access behavior is documented.

Written by the indexing model from the issue text.