docs: updates ahead of v0.1.0

[aryarm]

some changes we should make to the docs ahead of our new haptools release:

• describe where the example and test files are
• mention that hex codes can be provided to karyogram
• explain how the --verbosity flag works on the front page of our docs
• motivate the need for a .hap file format
• change default verbosity mentioned in __main__.py. Currently it says "only errors"
• more clearly link to files for simgenotype in the docs for it?
• tone down language about automatically supporting 1000G files
  say that we support 1000G file formats, but do not implement anything within haptools that specifically supports 1000 Genomes
• fix the link to the beagle map files. I think it's broken
• on the front page, consider linking to the github-hosted pipeline image instead of linking from google drive? to reduce chance of the image not loading