docs/: Restore doc of xmc4200 and xmc4400 in legacy section.#423

LinjingZhang wants to merge 2 commits into

4.0.0-pre-releaseInfineon/XMC-for-Arduino:4.0.0-pre-releasefrom

4.0.0-doc-improveInfineon/XMC-for-Arduino:4.0.0-doc-improveCopy head branch name to clipboard