chore: Added README with common issues

README.md

@@ -0,0 +1,7 @@
+# SSH Key issues
+
+Here are some things to check when running into ssh key issues:
+
+- Make sure that known hosts only contains a key of type ecdsa-sha2-nistp256 otherwise flux will fail to connect to the repository over ssh.
+
+- Make sure the deploy key is read/write.