Redirect /getting-started/use-cases/mix-and-match-database/ to the introduction page (#878)

Author: stktung

docs/.vuepress/public/_redirects

@@ -199,6 +199,8 @@
 /getting-started.html                   /getting-started/quickstart/                    301
 /getting-started/                       /getting-started/quickstart/                    301
 
+/getting-started/use-cases/mix-and-match-database/    /getting-started/use-cases/mix-and-match-database/introduction.html   301
+
 # Project types
 /project-types.html                     /                                               301