Add {url:parameter:} placeholder for extracting query parameters

common/src/commonMain/kotlin/com/artemchep/keyguard/common/service/placeholder/impl/UrlPlaceholder.kt

@@ -55,6 +55,18 @@ class UrlPlaceholder(
                 .let(::io)
         }
 
+        key.startsWith("url:parameter:", ignoreCase = true) -> {
+            val name = key.substringAfter("url:parameter:")
+            uuu.parameters[name]
+                .let(::io)
+        }
+
+        key.startsWith("base:parameter:", ignoreCase = true) -> {
+            val name = key.substringAfter("base:parameter:")
+            uuu.parameters[name]
+                .let(::io)
+        }
+
         key.equals("url:userinfo", ignoreCase = true) ||
                 key.equals("base:userinfo", ignoreCase = true) -> {
             val user = uuu.user.orEmpty()

wiki/PLACEHOLDERS.md

@@ -65,6 +65,7 @@ Note: `{base}` supports exactly the same parts as `{url}` and is identical to it
 | `url:userinfo` | User information: `user:pw` |
 | `url:username` | Username: `user` |
 | `url:password` | Password: `pw` |
+| `url:parameter:q` | Query parameter with a name `q`: `e` |
 
 #### Text transformation