Here's the current hotkeys (aka- keyboard shortcuts) supported in Lighthouse divided by Operating System (Mac vs. PC/Microsoft):
Note: keys to press are denoted in [ ]'s so [cntrl] = the control key & [H] = the letter H.

FOR PC/WINDOWS USERS
Bold: [Cntrl] + [B]
Italics: [Cntrl] + [i]
Underline: [Cntrl] + [U]
Start a bulleted list: [Cntrl] + [8]
Start a numbered list: [Cntrl] + [7]
End a list: press [Enter] twice
Create a hyperlink: [Ctrl]+L
Indent: press [Tab]

FOR MAC USERS
Bold: [Cmd] + [B]
Italics: [Cmd] + [i]
Underline: [Cmd] + [U]
Start a bulleted list: [Cmd] + [8]
Start a numbered list: [Cmd] + [7]
End a list: press [Enter] twice
Create a hyperlink: [Cmd] + [L]
Indent: press [Tab]