[Docs] Links in props tables can exist without their target

[chandlerprall]

For example, go to the data grid in-memory settings doc and open the Props tab. leadingControlColumns links to the EuiDataGridControlColumn definition, but it doesn't exist on the page so clicking the link goes nowhere.

[elizabetdev]

Notice on this PR #5214 that @constancecchen linked the page this way:

eui/src/components/form/super_select/super_select.tsx

Line 77 in 91abf40

* Optional props to pass to the underlying [EuiPopover](/#/layout/popover).

Should we be linking in all Props tabs like [EuiPopover](/#/layout/popover) instead of #EuiPopover?

[cchaos]

We've usually used the #Component method when it's actually a nested type, like #EuiDataGridControlColumn. Not to an entirely separate component like the popover example. So I think technically both are still valid. Even swapping the # shortcut for a manual []() MD link, won't validate whether the anchor exists.