Add opcodes to "Lists" documentation

[shemnon]

Add a summary of used, pending, and proposed opcodes for the EVM.
Also adds a list describing each 16 opcode block,

Cute Animal Picture

[codecov-commenter]

Codecov Report

Patch and project coverage have no change.

Comparison is base (a620b0a) 74.01% compared to head (0a2bb2c) 74.01%.

Additional details and impacted files

@@           Coverage Diff           @@
##           master     #764   +/-   ##
=======================================
  Coverage   74.01%   74.01%           
=======================================
  Files         570      570           
  Lines       31557    31557           
=======================================
  Hits        23356    23356           
  Misses       8201     8201           

Flag	Coverage Δ
unittests	74.01% <ø> (ø)

Flags with carried forward coverage won't be shown. Click here to find out more.

☔ View full report in Codecov by Sentry.
📢 Do you have feedback about the report comment? Let us know in this issue.

[shemnon]

@SamWilsn @lightclient can I get a review on this?

[petertdavies]

I think this is a perfectly reasonable. In the long term it would be nice to auto generate from the specs, but we are nowhere near that at the moment.

[shemnon]

opcodes.md and opcode-blocks.md could be auto generated from the spec and other pages, but I think the more uniquely useful page is the pending-opcodes.md, where opcodes that are targeting the next release are laid out, and it could serve as an aid in final selection of opcode numbers.

[chfast]

We have applied changes in ethereum/evmone#665 and we are happy with it.

I'm only slightly concerned that there is some duplication of information in these 3 tables.