{tikz-knots} is for questions relating to the use of the knots library for TikZ, which is a part of the spath3 package.
The knots library for TikZ is written by Andrew Stacey. On CTAN it is part of the spath3 package for manipulating soft paths. Use this tag in combination with tikz-pgf for questions about using this library to draw knot diagrams with TikZ or if you are facing problems with installation.