Manual rewrite and presentation merge

[KrystalDelusion]

Closes YosysHQ-Docs/YosysHQ-Docs#30

There is a list of open todos being generated on the index page, which will need to be removed prior to merging (ideally after all the todos are done), also changing todo_include_todos = True to False in the conf.py. Most of these are for rewriting sections of text which have been moved from their previous location and need to be:

1. reflowed for consistency,
2. expanded on (having come from presentation slides), or
3. rewritten to be less academic and more web docs.

• Remove the old appnotes from the appendix, with any relevant information merged into main docs where appropriate.
• Tidy directories to not reference appnotes or presentation.
• Redo Test Suites page to instead discuss the included tests, rather than the very out of date external tests.
• Last few blocking TODOs (making sure scripts are up to date with recommended practices etc)

[KrystalDelusion]

Preview available on readthedocs/yosys, note that this preview is currently being built manually and won't automatically update with changes to this branch/pr. For up to date builds, use make docs locally.

[povik]

I saw some lines in the wip manual that looked pretty out-of-date. That part of the manual seems to yet get its rewrite but wanted to mention it anyway, just in case.

[KrystalDelusion]

I saw some lines in the wip manual that looked pretty out-of-date. That part of the manual seems to yet get its rewrite but wanted to mention it anyway, just in case.

Thanks @povik ! I'm not as familiar with the internals so having someone else look at it is very helpful.

[KrystalDelusion]

Closes #4200

[nakengelhardt]

CI failure is due to #4275, you can use output reg [AWIDTH-0:0] count as a workaround.

Although I think this alternative is the recommended style (and it works with both verific and read_verilog without warnings):

module addr_gen 
#(  parameter MAX_DATA=256,
    localparam AWIDTH = $clog2(MAX_DATA)
) ( input en, clk, rst,
	output reg [AWIDTH-1:0] addr
);