maybe point to PkgCacheInspector and to MethodAnalysis

[nsajko]

These seem to be useful sometimes when optimizing or debugging (pre)compilation of your and related packages:

https://github.com/timholy/MethodAnalysis.jl

https://github.com/timholy/PkgCacheInspector.jl

[gdalle]

Sounds good! Wanna make a PR?