upgrade holder to 2.0, update thumbnail examples in docs to fit inside containers
CSS docs page: backticks ==> <code>
Merge pull request #8188 from cvrebert/patch-1

CSS docs page: backticks ==> <code>
Merge pull request #8187 from imsky/3.0.0-wip

upgrade holder to 2.0, update thumbnail examples in docs to fit inside containers
components docs: backticks ==> <code>
Merge pull request #8189 from cvrebert/patch-2

components docs: backticks ==> <code>
Merge pull request #8184 from FLOKER/3.0.0-wip

redundant lines removed