feat(mapping): plug and expose API (#346)

Signed-off-by: Aaron Pham <contact@aarnphm.xyz>

lua/avante/api.lua

@@ -0,0 +1,27 @@
+local Utils = require("avante.utils")
+
+---@class avante.ApiToggle
+---@operator call(): boolean
+---@field debug ToggleBind.wrap
+---@field hint ToggleBind.wrap
+---
+---@class avante.Api
+---@field ask fun(): boolean
+---@field edit fun(): nil
+---@field refresh fun(): nil
+---@field toggle avante.ApiToggle
+
+return setmetatable({}, {
+  __index = function(t, k)
+    local module = require("avante")
+    ---@class AvailableApi: ApiCaller
+    ---@field api? boolean
+    local has = module[k]
+    if type(has) ~= "table" or not has.api then
+      Utils.warn(k .. " is not a valid avante's API method", { once = true })
+      return
+    end
+    t[k] = has
+    return t[k]
+  end,
+}) --[[@as avante.Api]]