chore: add usage without gramio in files

docs/.vitepress/config.mts

@@ -69,6 +69,10 @@ export default defineConfig({
 							},
 							{ text: "Media Upload", link: "/files/media-upload" },
 							{ text: "Media Input", link: "/files/media-input" },
+							{
+								text: "Usage without GramIO",
+								link: "/files/usage-without-gramio",
+							},
 						],
 					},
 					{ text: "Types", link: "/types/index.html" },

docs/files/usage-without-gramio.md

@@ -0,0 +1,47 @@
+# Usage without GramIO
+
+## Write you own type-safe TBA API wrapper with File uploading support!
+
+```ts
+import type { ApiMethods, TelegramAPIResponse } from "@gramio/types";
+import { isMediaUpload, convertJsonToFormData } from "@gramio/files";
+import { FormDataEncoder } from "form-data-encoder";
+
+const TBA_BASE_URL = "https://api.telegram.org/bot";
+const TOKEN = "";
+
+const api = new Proxy({} as ApiMethods, {
+    get:
+        <T extends keyof ApiMethods>(_target: ApiMethods, method: T) =>
+        (params: Parameters<ApiMethods[T]>[0]) => {
+            const reqOptions: RequestInit = {
+                method: "POST",
+                duplex: "half",
+            };
+
+            if (isMediaUpload(method, params)) {
+                const formData = await convertJsonToFormData(method, params);
+
+                const encoder = new FormDataEncoder(formData);
+
+                reqOptions.body = encoder.encode();
+                reqOptions.headers = encoder.headers;
+            } else {
+                reqOptions.headers = {
+                    "Content-Type": "application/json",
+                };
+                reqOptions.body = JSON.stringify(params);
+            }
+
+            const response = await fetch(
+                `${TBA_BASE_URL}${TOKEN}/${method}`,
+                reqOptions
+            );
+
+            const data = (await response.json()) as TelegramAPIResponse;
+            if (!data.ok) throw new APIError({ method, params }, data);
+
+            return data.result;
+        },
+});
+```