PR: Documentation

[nelsonic]

• add standard readme (question) sections and background info Why? What? Who? How? #1
  See: https://github.com/dwyl/elixir-auth-google/tree/add-docs-issue-%2310
• add detailed (updated) instructions for creating a Google App:
  https://github.com/dwyl/elixir-auth-google/blob/add-docs-issue-%2310/create-google-app-guide.md
• add code docs to act as documentation on hex docs. Write Docs & Publish Package in Hex.pm #10
• Publish! https://hex.pm/packages/elixir_auth_google
• Create demo app: https://dashboard.heroku.com/apps/elixir-auth-google-demo
• Deploy demo 🚀 https://elixir-auth-google-demo.herokuapp.com/

before: https://github.com/dwyl/elixir-auth-google/tree/2b1f9b09433fb7845dff00f593edd8fa29825f5f
after: https://github.com/dwyl/elixir-auth-google/tree/71c022afee27e2cc377936c686538afa8e08d13e

[nelsonic]

@SimonLab we appear to not be able to run a bash script/command on GitHub CI
see: https://github.com/dwyl/elixir-auth-google/runs/325366614

Looks like there is a bit more work to send a report to Codecov using GitHub Actions ... 🤔
see: https://github.com/codecov/codecov-action

[nelsonic]

I've attempted to follow the official instructions for uploading the Codecov (excoveralls.json) file,
but still getting error https://github.com/dwyl/elixir-auth-google/commit/82d1d1f82be4a5509d050a03739e7a0542670c0c/checks?check_suite_id=334000821

@SimonLab can you help with getting this to work? (or can we switch to Travis-CI till we can get a working example app with all our standard tools including coverage...?) Thanks!

[nelsonic]

The latest build appears to pass:
https://github.com/dwyl/elixir-auth-google/commit/82d1d1f82be4a5509d050a03739e7a0542670c0c/checks?check_suite_id=334000821

But in actual fact it's failing to send the report to Codecov

It eventually gives up trying to upload and GitHub actions considers this to be a successful outcome.
This is a "false positive" which is the worst possible outcome from a CI system. 😞

[nelsonic]

Hi @SimonLab!
As discussed on standup, this Docs++ PR is done! 🚀
Please review/comment (and merge if OK) the other PRs #21 & #22 first.
And then once those are complete I will assign this one to you for review.
Thanks! ✨

[SimonLab]

I've added a few commits to fix some typos but otherwise looks great, thanks @nelsonic