CI: fix GitHub workflows

.github/workflows/main.yml

@@ -2,10 +2,10 @@ name: Main
 on:
   push:
     branches:
-      - master
+      - main
   pull_request:
     branches:
-      - master
+      - main
   workflow_dispatch:
 jobs:
   test:

package.yaml

@@ -1,10 +1,10 @@
 name:                icfpc-y2026
 version:             0.1.0.0
-github:              "githubuser/icfpc-y2026"
-license:             BSD-3-Clause
-author:              "Author name here"
-maintainer:          "example@example.com"
-copyright:           "2026 Author name here"
+github:              "codingteam/icfpc-y2026"
+license:             MIT
+author:              "codingteam"
+maintainer:          "https://github.com/codingteam"
+copyright:           "2026 codingteam"
 
 extra-source-files:
 - README.md
@@ -17,7 +17,7 @@ extra-source-files:
 # To avoid duplicated efforts in documentation and dealing with the
 # complications of embedding Haddock markup inside cabal files, it is
 # common to point users to the README.md file.
-description:         Please see the README on GitHub at <https://github.com/githubuser/icfpc-y2026#readme>
+description:         Please see the README on GitHub at <https://github.com/codingteam/icfpc-y2026#readme>
 
 dependencies:
 - base >= 4.7 && < 5