cashocs v2.0.0-alpha1

What's Changed

• Feature/display precision by @sblauth in #143
• [pre-commit.ci] pre-commit autoupdate by @pre-commit-ci in #144
• [pre-commit.ci] pre-commit autoupdate by @pre-commit-ci in #146
• Bump actions/checkout from 3.1.0 to 3.2.0 by @dependabot in #145
• Add pytest plugins for better testing by @sblauth in #148
• [pre-commit.ci] pre-commit autoupdate by @pre-commit-ci in #149
• Feature/space mapping docs by @sblauth in #150
• Feature/new demo docs by @sblauth in #152
• Add demo for io of xdmf files by @sblauth in #153
• Feature/xdmf docs by @sblauth in #154

Full Changelog: v2.0.0-alpha0...v2.0.0-alpha1