Change Case

Change case is a handy Google Docs Add-on that can perform six different changes on selected text, as shown below. If the last two are unfamiliar, sentence case is when you only capitalize the first letter of the first word and title case capitalizes the first letter of each word.

https://chrome.google.com/webstore/detail/change-case/ahpcjlihommmjokggmgpinfpflphlall