Release v1.3.1

* Add CNAME record and theme config for the project page
* Add PGP keys to CD workflow for signing the releases
* Update README.md about Copr package
-----BEGIN PGP SIGNATURE-----

iQEzBAABCAAdFiEEOeZ432O+IOpaF1FWuShyCuxTIRcFAl8h3roACgkQuShyCuxT
IRchLwgAg+wF4gVinEvgtXzsQUj/Y3wruvF9CsgRsgdNK12jjSIi3uZDNX/Q0g2b
2zj5fq9+Z8+Wkh1xV0F2o5/CFJwKHai0TRIBR68jXb0uaUjH7FReP7gpWTx+TIhR
hHS9SDZGvYZQSa+hTeF1cx3/e96W4CD89JYEjSxcCJaHuvWwuWm6HRWfV/+i23XK
ZJOE3jQ1Vu4/RtsMGMmKsTLkoo//3/c5ElKGc7d2UbQwkCAJDGooyxlAXBicGsrw
kw0xDZ7A6nxArrcWJY49k2BcRXgqvAT+pJLGIBqsW8zmY1X+vpVJAGZIsZVx15jL
de76lbfI+D5fNMAOiM1CPMe4LUXByA==
=mYGM
-----END PGP SIGNATURE-----