README.md: update & correct links to O'Reilly X Toolkit books (!66) · Merge requests · xorg / lib / libXt · GitLab

Alan Coopersmith requested to merge alanc/libxt:readme into master Sep 18, 2023

Fix volume 5 link to point to volume 5, not 4.
Fix volume 4 3rd edition link to point to 3rd ed. not 2nd.
Update links to drop "www." from hostname to avoid a redirect.

Reported-by: consolers on #xorg-devel IRC

Edited Sep 18, 2023 by Alan Coopersmith