Document new configuration key

docs/installation.md

@@ -89,6 +89,7 @@ Configuration keys:
 |---|---|
 |`promotionPaths`| Array of maps, each map describes a promotion flow|
 |`promotionPaths[0].sourcePath`| directory that holds components(subdirectories) to be synced, can include a regex.|
+|`promotionPaths[0].ComponentPathExtraDepth`| The number of extra nesting levels to add to the "components" being promoted, this allows nesting components in subdirectories while keeping them distinct |
 |`promotionPaths[0].conditions` | conditions for triggering a specific promotion flows. Flows are evaluated in order, first one to match is triggered.|
 |`promotionPaths[0].conditions.prHasLabels` | Array of PR labels, if the triggering PR has any of these labels the condition is considered fulfilled. Currently it's the only supported condition type|
 |`promotionPaths[0].promotionPrs`|  Array of structures, each element represent a PR that will be opened when files are changed under `sourcePath`. Multiple elements means multiple PR will be opened|