chore: Public repo preparation

[lorenjohnson]

• Transcribes CODE_OF_CONDUCT.md, CONTRIBUTING.md, and LICENSE from hylo-evo. Adds note in README referencing these (copied from hylo-evo)
• Removes the release walkthrough video link. I'm pretty sure this at least visually may show things that are not public--that note and link is now in a 1Password as a secure note (will send link in Slack).
• Removes Fastlane entirely. This was used for iOS certificate provisioning which I've now setup to be automatic, but it was also setup for automatically pushing releases to the store, which hadn't worked or been used in some time. It needed to go anyway, but within the static files it included the login/password to the demo account.

Once this is merged, do the following:

• Go to https://sentry.io/settings/account/api/auth-tokens as dev@hylo.com, regenerate our token, and update the value for SENTRY_AUTH_TOKEN in your local .env and in the project level Bitrise Workflow env vars accordingly.

NOTE: Look to 1Password for latest HYLO_REACT_NATIVE env file, there are a couple Sentry properties you'll need there to do Archive builds locally without failure (not an issue for normal dev builds).

[thomasgwatson]

lgtm

[lorenjohnson]

Ah! I had almost forgotten about the sentry.properties files which @tibetsprague you astutely identified in your analysis in #353. The need for these files was actually deprecated in the last Sentry update I made, and I had forgotten to delete them already. Deleted now as part of this PR. These files remain but everything but a default value has been moved into env vars, the current version of the Sentry React Native plugin fails if these files don't exist though all of the relevant values can otherwise be in env vars which they now are.

[gitguardian]

⚠️ GitGuardian has uncovered 6 secrets following the scan of your pull request.

Please consider investigating the findings and remediating the incidents. Failure to do so may lead to compromising the associated services or software components.

🔎 Detected hardcoded secrets in your pull request

GitGuardian id	GitGuardian status	Secret	Commit	Filename
11948920	Triggered	Sentry User Auth Token	db79fc9	ios/sentry.properties	View secret
11948920	Triggered	Sentry User Auth Token	db79fc9	android/sentry.properties	View secret
11948920	Triggered	Sentry User Auth Token	78ff5fc	ios/sentry.properties	View secret
11948920	Triggered	Sentry User Auth Token	83c4c69	ios/sentry.properties	View secret
11948920	Triggered	Sentry User Auth Token	83c4c69	android/sentry.properties	View secret
11948920	Triggered	Sentry User Auth Token	78ff5fc	android/sentry.properties	View secret

🛠 Guidelines to remediate hardcoded secrets

1. Understand the implications of revoking this secret by investigating where it is used in your code.
2. Replace and store your secrets safely. Learn here the best practices.
3. Revoke and rotate these secrets.
4. If possible, rewrite git history. Rewriting git history is not a trivial act. You might completely break other contributing developers' workflow and you risk accidentally deleting legitimate data.

To avoid such incidents in the future consider

• following these best practices for managing and storing secrets including API keys and other credentials
• install secret detection on pre-commit to catch secret before it leaves your machine and ease remediation.

---

^{🦉 GitGuardian detects secrets in your source code to help developers and security teams secure the modern development process. You are seeing this because you or someone else with access to this repository has authorized GitGuardian to scan your pull request.}

[lorenjohnson]

@tibetsprague this is pending your review as this two me is a good one for "2 reviewers". However I did 2 more places I need to move secrets android/app/src/main/java/com/hylo/hyloandroid/MainApplication.java and ios/HyloReactNative/AppDelegate.mm where there are Intercom API keys and IDs. Will handle that shortly. If you review before then assume that is taken care of, if that makes sense.

[tibetsprague]

amazing!

[lorenjohnson]

Merged with comment on #353 for remaining tasks