Update docs/installation.md

Co-authored-by: coderabbitai[bot] <136622811+coderabbitai[bot]@users.noreply.github.com>

Author: ildyria

docs/installation.md

@@ -29,7 +29,7 @@ The Lychee gallery has a few system requirements. You will need to make sure you
 	- imagick (optional — to generate better thumbnails)
 	- json
 	- libxml
-  - ldap (**new since 7.3**)
+	- ldap (**new since 7.3**)
 	- mbstring
 	- openssl
 	- pcre