feat: json2go (#130)

* feat(json2go): implement

* feat(json2go): support manual input

* chore(readme): add json2go

* chore(docs): add docs

spec/integration/json2go_test.lua

@@ -0,0 +1,25 @@
+local t = require "spec.testutils"
+local child, T, json2go = t.setup "json2go"
+
+json2go["should convert interativly"] = function()
+  local rs = t.setup_test("json2go/interativly", child, { 2, 0 })
+  child.cmd "GoJson"
+  child.type_keys [[{"json": true}]]
+  child.type_keys "<Esc>"
+  child.cmd "wq" -- quit prompt
+  child.cmd "write" -- the fixture file
+
+  t.eq(t.readfile(rs.tmp), rs.fixtures.output)
+  t.cleanup(rs)
+end
+
+json2go["should convert argument"] = function()
+  local rs = t.setup_test("json2go/manual", child, { 2, 0 })
+  child.cmd [[GoJson {"user": {"name": "user-ovic"}}]]
+  child.cmd "write"
+
+  t.eq(t.readfile(rs.tmp), rs.fixtures.output)
+  t.cleanup(rs)
+end
+
+return T