add initial version of pandoc filter

langfilter/langfilter.cabal

@@ -0,0 +1,23 @@
+cabal-version: 2.2
+name: langfilter
+version: 0.1.0
+synopsis: filter for conlang stuff
+license: AGPL-3.0-or-later
+
+author: Rhiannon Morris <rhi@rhiannon.website>
+maintainer: Rhiannon Morris <rhi@rhiannon.website>
+
+executable langfilter
+  hs-source-dirs: .
+  main-is: langfilter.hs
+  ghc-options:
+    -Wall -threaded -rtsopts -with-rtsopts=-N
+  default-language: Haskell2010
+  default-extensions:
+    BlockArguments,
+    LambdaCase,
+    PatternSynonyms,
+    ViewPatterns
+  build-depends:
+    base ^>= 4.14.0.0,
+    pandoc-types == 1.17.*