feat(iferr): add -message support (#89)

* feat(iferr): add *-message* support

* generate docs

lua/gopher/config.lua

@@ -66,6 +66,11 @@ local default_config = {
     -- default tags to add to struct fields
     default_tag = "json",
   },
+  iferr = {
+    -- choose a custom error message
+    ---@type string|nil
+    message = nil,
+  },
 }
 --minidoc_afterlines_end
 

lua/gopher/iferr.lua

@@ -15,7 +15,13 @@ function iferr.iferr()
   local pos = vim.fn.getcurpos()[2]
   local fpath = vim.fn.expand "%"
 
-  local rs = r.sync({ c.commands.iferr, "-pos", curb }, {
+  local cmd = { c.commands.iferr, "-pos", curb }
+  if c.iferr.message ~= nil and type(c.iferr.message) == "string" then
+    table.insert(cmd, "-message")
+    table.insert(cmd, c.iferr.message)
+  end
+
+  local rs = r.sync(cmd, {
     stdin = u.readfile_joined(fpath),
   })