docs: better explain the architecture and more clearly separate docker setup from lndmon setup (mermaid version)

[ZZiigguurraatt]

This is an alternative to #123 that uses mermaid charts instead of https://app.monosketch.io to diagram the monitoring architecture.

@Roasbeef , @saubyk , @djkazic , please take a look!

[ZZiigguurraatt]

Looks like it doesn't render well in GitHub "dark mode". Is that an issue for all mermaid charts?

[saubyk]

LGTM

Regarding the rendering of mermaid charts in dark mode, you can look up suggestions on any of the LLM tools, it may be improved marginally.

I iterated a lot to improve the mermaid chart on this doc, if it's any help: https://github.com/lightningnetwork/lnd/blob/master/docs/db_migration_guide.md

[Roasbeef]

Why remove install.md?

[ZZiigguurraatt]

The reason I changed the name is because the general install stuff was mostly moved to README.md and everything else related was docker specific.

[Roasbeef]

Favor keeping the name of INSTALL.md, but general doc improvement I'd say. You can get the diagram to render better in dark mode by using different colors.

[ZZiigguurraatt]

Force pushed a commit that removes a few lines that were added by the web mermaid chart editor I was using. The colors now look good in both light and dark mode.

[ZZiigguurraatt]

Favor keeping the name of INSTALL.md, but general doc improvement I'd say. You can get the diagram to render better in dark mode by using different colors.

The reason I changed the name is because the general install stuff was mostly moved to README.md and everything else related was docker specific.

[ZZiigguurraatt]

Who do we need to merge now that @Roasbeef has approved? @djkazic, are you able to do it?