Update docs for the minimum version of Ruby to 2.7
While !2633 (merged) upgrades Ruby to 2.7, docs for the minimum version of Ruby has not been updated.
Updating the docs is required.
Edited by Takuya Noguchi
While !2633 (merged) upgrades Ruby to 2.7, docs for the minimum version of Ruby has not been updated.
Updating the docs is required.