[doc/sysadmin] add instruction to support webp
[doc/sysadmin] add instruction to support webp

Changes were performed on integration and core.

Resources:
- https://www.iana.org/assignments/media-types/media-types.xhtml webp
  is still not listed there
- https://github.com/python/cpython/pull/29259 was merged 3 days ago

mcolom/ipolDevel,mcolom/ipolDevel,mcolom/ipolDevel,mcolom/ipolDevel