Add logos; fix PyPI documentation link; update dependencies

[jat255]

Two small things and one (slightly) larger thing:

• Add dark/light variant logos that can be used on hyperspy.org (see Add ETSpy to ecosystem table hyperspy/hyperspy-website#69)
• Fix link in documentation that is broken on pypi.org (will require a 1.0.1 release to fix)
• Bumped version to 1.0.1
• Fix badge in readme from anaconda that isn't updating (see Anaconda.org version badge doesn't get updated ContinuumIO/anaconda-issues#10231)
• relaxes requirements of numpy to >1.26 and astra-toolbox to >2.1.
  • this was slightly difficult to test, but in local testing, when installed on my linux system using conda (with and without GPU), all the tests pass using astra-toolbox=2.1.2 and numpy=1.26.4
  • Alongside Relax astra-toolbox and numpy versions conda-forge/etspy-feedstock#4, this PR should allow installation of CIL alongside ETSpy

Resolves #14