Versioning LATEST => 75.0.3770.140

It would probably be more useful for readers to refer to a real version in addition to the default of LATEST

Author: Kelly Selden

README.md

@@ -229,6 +229,12 @@ Another option is to use env variable `CHROMEDRIVER_VERSION`.
 CHROMEDRIVER_VERSION=LATEST npm install chromedriver
 ```
 
+You can also force a different version of chromedriver by replacing `LATEST` with a version number:
+
+```shell
+CHROMEDRIVER_VERSION=75.0.3770.140 npm install chromedriver
+```
+
 ## A Note on chromedriver
 
 Chromedriver is not a library for NodeJS.