chore(docs): Add first version of architecture doc

[adizere]

Part of #375

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PR author checklist

• Reference GitHub issue
• Ensure PR title follows the conventional commits spec

[cason]

Great.

We have some nomenclature problems, as usual, ehe.

There is a reference to a Broadcast effect that I could not find in the referred source file.

[cason]

I wonder whether this document should go into the docs/ directory.

[adizere]

I wonder whether this document should go into the docs/ directory.

Architecture.md can be seen as a prerequisite to anything that exists in docs/.

[greg-szabo]

I've fixed/renamed/updated all outstanding items. The only point I'd like to rehash is where the ARCHITECTURE.md resides. I would still put it in the docs folder because, at one point, we will publish the docs as a website, and if everything is in one place, it makes the process much smoother. (Also, updating documentation is easier if everything is in one place.)

We could leave a placeholder ARCHITECTURE.md in the root folder, pointing to the one in the docs folder.

At least, that's my 2 cents.

[adizere]

I have no particular opinions where architecture.md should sit between top-level and within docs/. Both are fine.

If no one takes a decision/merges by tmrw morning (CET), I'll go ahead and leave as it (at top level) and merge this.

[romac]

Let's put it in docs to not scatter documentation in multiple places. We can always link to it from the readme.

[romac]

Nevermind, let's leave it where it is, nice to have at the top-level.