Fix broken links and add TheCodeForge programming resource

[tracedynamics]

Fixed broken links:

• thinkster.io (DNS dead) → replaced with freeCodeCamp
• codelobster.com (DNS dead) → removed the dead link
• selftaughtornot.com (SSL error) → replaced with YouTube playlist mirror
• codementor.io/experts (404) → replaced with codementor.io homepage
• codementor.io/events/ (404) → replaced with codementor.io homepage
• linkedin-learning.pxf.io/eWX26 (404) → replaced with linkedin.com/learning/
• ide.new/cpp (DNS dead) → removed the dead entry
• CoenraadS.bracket-pair-colorizer (VSCode extension, 404) → replaced with working Rainbow Brackets extension
• labex.io (403) → kept as-is, noted may be behind auth

Added resource:

• TheCodeForge (thecodeforge.io) → added in Sites - Coding Platforms section between FreeCodeCamp and Scrimba. Features 1,600+ free programming tutorials across 13 categories.