Update website and add code of conduct

[tfr42]

Taken from https://docs.google.com/presentation/d/1imiG7x09ry7lGvmS15FCVq2Z7yaICY00fcpXBK27TXY/edit#slide=id.g3fdcab0c8e_168_0, slide 54, comments:

Jody Garnett
11:27 24 Aug
Checking the website - that is a BIG osgeo project logo (there is svg if you want a smaller size)

Jody Garnett
11:28 24 Aug
We do ask that all committees including project committees adopt a code of conduct - there is some guidance here https://www.osgeo.org/code_of_conduct/

Jody Garnett
11:29 24 Aug
It took some time to find the source code link to https://github.com/deegree/deegree3
That all looks great, when you do decide on a code of conduct you may wish to add it here also.

[stephanr]

For the next meeting I will create a pull-request to match the logo sizes.