Update update documentation

Author: zswaff

admin/README.md

@@ -40,3 +40,5 @@
 
 1. Update node, replace the current version in `dockerfile` with the latest stable version [here](https://nodejs.org/en/download)
 2. Run `yarn req-up-all` and select everything to update all FE dependencies
+3. Manually set the versions in `dependencies`, but not `devDependencies`, to be `~` the lowest functional minor version
+4. Run `yarn install`