Hey hey!

There's this bash_profile alias I've been using and probably it's helpful for you too:

For MacOS:

alias gh="open \`git remote -v | grep git@github.com | grep fetch | head -1 | cut -f2 | cut -d' ' -f1 | sed -e's/:/\//' -e 's/git@/http:\/\//'\`"

For Linux (provided by Shawn McElroy in the comments, thank you):
alias gh="$BROWSER $(git remote -v | grep git@github.com | grep fetch | head -1 | cut -f2 | cut -d' ' -f1 | sed -e's/:/\//' -e 's/git@/http:\/\//'\)"

After that, just use the command gh. It will open your browser with the currently active Git project in Github.