Add _redirects file

Used for redirecting city domains (which point to the same Netlify deployment) to their city in the country domain instead, to not have duplicate content under multiple domains.

[skip ci]

Author: sisou

public/_redirects

@@ -0,0 +1,10 @@
+# Germany
+https://kryptostadt-mannheim.de/*    https://kryptostadt.info/de/cities/mannheim    301!
+https://kryptostadt-muenchen.de/*    https://kryptostadt.info/de/cities/muenchen    301!
+https://kryptostadt.berlin/*         https://kryptostadt.info/de/cities/berlin      301!
+
+# Canada
+#https://cryptocity-montreal.com/*    https://cryptocity-canada.com/en/cities/montreal    301!
+
+# Slovenia
+#https://cryptocity-ljubljana.com/*    https://cryptocity-slovenia.com/en/cities/ljubljana  301!