Fix local FS cache config name

Author: DarthSim

versioned_docs/version-4-pre/cache/internal/local_filesystem.mdx

@@ -7,13 +7,13 @@ description: Learn about how to configure the local filesystem cache in imgproxy
 imgproxy can store cached images on the local filesystem. To use filesystem cache, do the following:
 
 1. Set the `IMGPROXY_CACHE_USE` environment variable to `fs`.
-2. Set `IMGPROXY_CACHE_LOCAL_FILESYSTEM_ROOT` to your cache directory path.
+2. Set `IMGPROXY_CACHE_FS_ROOT` to your cache directory path.
 3. _(optional)_ Specify a path prefix for cache files with `IMGPROXY_CACHE_PATH_PREFIX`.
 
 ### Configuration
 
 * `IMGPROXY_CACHE_USE`: set to `fs` to enable local filesystem cache.
-* `IMGPROXY_CACHE_LOCAL_FILESYSTEM_ROOT`: the root directory for filesystem cache. Default: blank
+* `IMGPROXY_CACHE_FS_ROOT`: the root directory for filesystem cache. Default: blank
 * `IMGPROXY_CACHE_PATH_PREFIX`: a path prefix for the cache files. This can be useful to organize cache files in a specific directory structure. Default: blank
 * `IMGPROXY_CACHE_BUCKET`: When using the filesystem adapter, this can be used as an additional path component. Default: blank
 * `IMGPROXY_CACHE_KEY_HEADERS`: a comma-separated list of HTTP request headers to include in the cache key. This allows caching different versions of the same image based on request headers. Default: blank
@@ -22,8 +22,8 @@ imgproxy can store cached images on the local filesystem. To use filesystem cach
 
 ### Example
 
-Assume you want to cache processed images in `/var/cache/imgproxy`. Run imgproxy with `IMGPROXY_CACHE_LOCAL_FILESYSTEM_ROOT` set to your cache directory:
+Assume you want to cache processed images in `/var/cache/imgproxy`. Run imgproxy with `IMGPROXY_CACHE_FS_ROOT` set to your cache directory:
 
 ```bash
-IMGPROXY_CACHE_USE=fs IMGPROXY_CACHE_LOCAL_FILESYSTEM_ROOT=/var/cache/imgproxy imgproxy
+IMGPROXY_CACHE_USE=fs IMGPROXY_CACHE_FS_ROOT=/var/cache/imgproxy imgproxy
 ```

versioned_docs/version-4-pre/configuration/options.mdx

@@ -457,7 +457,7 @@ Read the [Internal cache guide](../cache/internal.mdx) for more info.
 
 imgproxy can store cached images on the local filesystem. To use [filesystem cache](../cache/internal/local_filesystem.mdx), set `IMGPROXY_CACHE_USE` to `fs`:
 
-* [`IMGPROXY_CACHE_LOCAL_FILESYSTEM_ROOT`]: ((pro)) the root directory for filesystem cache. Default: blank
+* [`IMGPROXY_CACHE_FS_ROOT`]: ((pro)) the root directory for filesystem cache. Default: blank
 
 See full documentation in [Cache storage: Local filesystem](../cache/internal/local_filesystem.mdx).