Implement messages

Implement messages almost the same as in the Rust version, only with
YAML instead of TOML this time, and a regular old mustache template
instead of something handrolled. Besides that, pretty much everything
here is the same.

package.yaml

@@ -15,8 +15,12 @@ category:            Game
 description:         Please see the README on GitHub at <https://github.com/glittershark/xanthous>
 
 dependencies:
-- QuickCheck
 - base
+
+- aeson
+- QuickCheck
+- quickcheck-text
+- quickcheck-instances
 - brick
 - checkers
 - classy-prelude
@@ -24,14 +28,24 @@ dependencies:
 - containers
 - data-default
 - deepseq
+- file-embed
 - generic-arbitrary
 - generic-monoid
 - groups
 - lens
+- megaparsec
+- MonadRandom
 - mtl
+- random
+- raw-strings-qq
+- reflection
+- stache
+- tomland
 - vty
+- yaml
 
 default-extensions:
+- BlockArguments
 - ConstraintKinds
 - DataKinds
 - DeriveAnyClass
@@ -51,13 +65,13 @@ default-extensions:
 - PolyKinds
 - RankNTypes
 - ScopedTypeVariables
+- TupleSections
 - TypeApplications
 - TypeFamilies
 - TypeOperators
 
 ghc-options:
 - -Wall
-- -threaded
 
 library:
   source-dirs: src
@@ -67,6 +81,10 @@ executable:
   main: Main.hs
   dependencies:
   - xanthous
+  ghc-options:
+  - -threaded
+  - -rtsopts
+  - -with-rtsopts=-N
 
 tests:
   test: