[doc] Lists: Do not decrease font size
[doc] Lists: Do not decrease font size

There's no typographical reason to decrease the font size as we go down
the hierarchy of ordered/unordered lists. Content on the second
hierarchy level is equally important and should be equally readable as
the normal text. The docs are no PowerPoint presentation.

Signed-off-by: Philipp Wagner <5a4b10454c30419e54a1570be358a516ff84bb63@lowrisc.org>

lowRISC/opentitan,lowRISC/opentitan,lowRISC/opentitan,lowRISC/opentitan,lowRISC/opentitan,lowRISC/opentitan