Add doc/doxygen to .gitignore
Update comments in addrman to be doxygen compatible

Also correct the file license
[Qt] Remove CAmount from BitcoinAmountField Q_PROPERTY
Merge pull request #5117

7014f38 [Qt] Remove CAmount from BitcoinAmountField Q_PROPERTY (Cozz Lovan)
Merge pull request #5131

24f5c94 Update comments in addrman to be doxygen compatible (Michael Ford)
c772f4c Add doc/doxygen to .gitignore (Michael Ford)