docs(self-hosted configuration): rewrite cacheDir section (#15508)

docs/usage/self-hosted-configuration.md

@@ -147,13 +147,13 @@ Unsupported tools will fall back to `binarySource=global`.
 
 ## cacheDir
 
-By default Renovate uses a temporary directory like `/tmp/renovate/cache` to store cache data.
+By default Renovate stores cache data in a temporary directory like `/tmp/renovate/cache`.
 Use the `cacheDir` option to override this default.
 
-The `baseDir` and `cacheDir` option do not need to point to the same directory.
-You can use one directory for the repo data, and another for the the cache data.
+The `baseDir` and `cacheDir` option may point to different directories.
+You can use one directory for the repo data, and another for the cache data.
 
-e.g.
+For example:
 
 ```json
 {