Merge pull request #5262 from Iisus/doc-fedora-install

Update Fedora repo in the install guide

Author: snoyberg

doc/install_and_upgrade.md

@@ -141,8 +141,8 @@ Use the [generic Linux option](#linux).
 
 There is also an
 unofficial
-[Fedora Copr repo](https://copr.fedoraproject.org/coprs/petersen/stack/) which
-can be enabled with: `sudo dnf copr enable petersen/stack`. Note that this Stack
+[Fedora Copr repo](https://copr.fedoraproject.org/coprs/petersen/stack2/) which
+can be enabled with: `sudo dnf copr enable petersen/stack2`. Note that this Stack
 version may lag behind, so we recommend running `stack upgrade` after installing
 it.