update Tools page

[VladimirAlexiev]

(Related: #90)

@nicholascar @PapoutsoglouE
The https://www.w3.org/groups/wg/data-shapes/tools/ page needs lots of updates:

• has a wiki link with a strange description and then "Warning: This wiki has been archived and is now read-only."
• Points to both https://github.com/w3c/data-shapes and https://github.com/w3c/shacl but the two should be merged, and the former should be archived
  • Clarify relationship between this repo and w3c/shacl data-shapes#162: has a sort of plan how to do the merge
  • Which github repo to use? data-shapes#157
• doesn't point to https://irc.w3.org/ channel #data-shapes (maybe that belongs in https://www.w3.org/groups/wg/data-shapes/calendar/)