PHP 8 & other fixes

What's Changed

• Fix for multisite redirect (#180) by @cristianuibar in #181
• Fix hardcoded temp by @DenisFlorin in #187
• Fix deprecated create function by @DenisFlorin in #188
• added instuctions of instalation inside the docs by @alongouldman in #174
• Add gitium_git_bin_path filter by @cristianuibar in #139
• Update readme.txt by @annamradu in #150

New Contributors

• @DenisFlorin made their first contribution in #187
• @alongouldman made their first contribution in #174

Full Changelog: 1.0.2...1.0.3