refactor(docs): split Flex Instruction Manual into more pages

[ecormany]

Overview

The chapters of the Flex manual were great for a PDF book. They are toooooo long for web-based docs. This fixes that.

Test Plan and Hands on Testing

Sandbox.
Examining warnings from mkdocs build but not overly fussed about them now.

Changelog

• Splits up installation, system description, modules, protocol development, software, and maintenance chapters.
• Big rewrite of labware chapter to stop duplicating Labware Library content.
• Moves the entire manual from flex-manual -> flex for better URLs.

Review requests

• Check links.
• Check prose, especially at the start and end of pages which might have retained transitions across sections that no longer make sense when they're on a separate page.
• Please take a special look at the Labware chapter, which had the most rewriting as opposed to refactoring.

Risk assessment

low-med. docs only but could've broken some internal links or something.

[jwwojak]

Removing all the specific labware stuff is a real improvement as is the new organization.

I only have comments about multiple instances of linked "Labware Library" references on the same page when we might be able to get away with doing that once, on first mention only.

Here's where it shows up as linked text multiple times:

• index.md: 2
• concepts.md: 2
• types.md: 3

Not many instances, but when combined with other links, a page can look cluttered.

[ecormany]

Ready for review. Doing a self-review (i.e., proofread and checking links) throughout the day today.

[y3rsh]

Test this branch here:

http://sandbox.docs.s3-website.us-east-2.amazonaws.com/docs-flex-manual-refactor

Let us make sure the build and publish looks good.

[emilyburghardt]

Took a stroll through the sandbox and left a few comments- some nitpicks, mostly small things that aren't building right. can be picked up easily after this is merged, too.

[emilyburghardt]

super nitpick that can be ticketed for later, but in the current manual these headers (choose pipette type/ prepare for installation etc.) really pop with the different text/color. Here, they look like plain text, so we could add some different style element like we had before.

[ecormany]

Yeah, this is directly following our web typography standards. I think we should feel free to modify if things are too same-y, to the point of making the text harder to read.

[ecormany]

addressing these in #19163, thanks for spotting tho!