Update 'Sed.md'

Sed.md

@@ -16,4 +16,22 @@ sed -i -e 's/PHPver/'$phpver'/' <FileName>
 Example:
 ```
 sed -i -e 's/PASSword/'$PASSword'/' <FileName>
+```
+
+### DBName: shoud be replaced with $db_name
+Example:
+```
+sed -i -e 's/DBName/'$db_name'/' <FileName>
+```
+
+### DBUser: shoud be replaced with $db_user
+Example:
+```
+sed -i -e 's/DBUser/'$db_user'/' <FileName>
+```
+
+### DBPass: shoud be replaced with $db_pass
+Example:
+```
+sed -i -e 's/DBPass/'$db_pass'/' <FileName>
 ```