Unrelated History in Git and resolve "fatal: refusing to merge unrelated histories"

@lynxbee Two different independent repositories with separate contents committed at local git and git at remote server when tried to merge together shows error "fatal: refusing to merge unrelated histories" because both had differenet histories. Understand what is unrelated history in git and learn about how to fix the merge error "fatal: refusing to merge unrelated histories" More details https://lynxbee.com/fatal-refusing-to-merge-unrelated-histories/