Documentation

[bitmarkcc]

For building with Ubuntu 22, gcc-11 (the default) fails. Thus we should instruct users to use gcc version <= 10 for now. Also the windows README shows an incorrect Bitmark version number. Solution: bitmarkcc@df1e617 and bitmarkcc@d58aa6a

[bitmarkcc]

Note: This may not be needed anymore (see issue #131)

[bitmarkcc]

If we want to accept the Ubuntu 22 compatibility changes (issue #131) then we should change the documentation a bit. Here is my change: bitmarkcc@10acf2c