reference(env vars): add CC_CACHE_DEPENDENCIES_EXTRA_PATHS

Author: davlgd

content/doc/reference/reference-environment-variables.md

@@ -63,6 +63,7 @@ You can set some tools' version in any runtime (except Docker):
 |  Name  |  Description  |  Default value  |
 |-----------------------|------------------------------|--------------------------------|
 |`CC_CACHE_DEPENDENCIES` | Enable caching of your build dependencies to speed up following builds. | false |
+|`CC_CACHE_DEPENDENCIES_EXTRA_PATHS` | Adds additional paths to dependencies cache, relative to the application folder, separated by a `:` (e.g. `vendor:../dependencies`) |  |
 |[`CC_DISABLE_BUILD_CACHE_UPLOAD`](../../develop/env-variables/#settings-you-can-define-using-environment-variables "Settings you can define using environment variables") | Disable creation and upload of cache archive. Restarts won't be speeded up. | `false` |
 |[`CC_IGNORE_FROM_BUILDCACHE`](../../develop/env-variables/#settings-you-can-define-using-environment-variables "Settings you can define using environment variables") | Allows to specify paths to ignore when the build cache archive is created. |  |
 |[`IGNORE_FROM_BUILDCACHE`](../../develop/env-variables/#settings-you-can-define-using-environment-variables "Settings you can define using environment variables") | (Deprecated) Allows to specify paths to ignore when the build cache archive is created. |  |

shared/cached-dependencies.md

@@ -2,7 +2,12 @@
 
 #### Enabling dependencies caching
 
-You can enable dependencies caching by adding the `CC_CACHE_DEPENDENCIES=true` [environment variable](#setting-up-environment-variables-on-clever-cloud) in your application. It is enabled by default only for rust and haskell applications.
+You can enable dependencies caching by adding the `CC_CACHE_DEPENDENCIES=true` [environment variable](#setting-up-environment-variables-on-clever-cloud) in your application. It's enabled by default only for Haskell and Rust applications.
+
+To add folders to the dependencies cache, use `CC_CACHE_DEPENDENCIES_EXTRA_PATHS`. These paths should comply with the following rules:
+- Be a subdirectory of the `$HOME` directory
+- Be relative to the application root directory (e.g. `vendor`, `../dependencies`)
+- Be separated by a `:` if you want to add multiple paths (e.g. `CC_CACHE_DEPENDENCIES_EXTRA_PATHS=vendor:../dependencies`)
 
 #### Disabling dependencies caching