Instance template (#33)

* protocol instance template [WIP]

* protocol instances template

* add methods to check correctness of participant types in protocol TH

* PushConfirm and and PushMsg implementation types

* check Command type + doctest

definitions/package.yaml

@@ -19,7 +19,9 @@ ghc-options:
   - -Wincomplete-uni-patterns
 
 default-extensions:
+  - BlockArguments
   - DuplicateRecordFields
+  - LambdaCase
   - NamedFieldPuns
   - NoImplicitPrelude
   - OverloadedStrings
@@ -35,10 +37,12 @@ dependencies:
   - servant-docs
   - servant-server
   - template-haskell
+  # - pretty-show
 
 library:
   source-dirs: src
   exposed-modules:
+    - Predicate
     - Simplex.Messaging.Types
     - Simplex.Messaging.ServerAPI
 
@@ -46,3 +50,12 @@ executables:
   api-docs:
     source-dirs:      src
     main:             Main.hs
+
+tests:
+  simplex-definitions-doctests:
+    source-dirs: tests
+    main: doctest-driver.hs
+    ghc-options: -threaded
+    dependencies:
+      - doctest
+      - doctest-driver-gen