docs: added token.md

docs/02-Guides/token.md

@@ -0,0 +1,41 @@
+---
+sidebar_position: 3
+---
+
+# Creating a Token
+
+A **Token** is what we use when we transfer money from one wallet to another. Technically speaking a **Token** is an object containing a list of [Proofs](https://github.com/cashubtc/nuts/blob/main/00.md#proof) and a URL of the corresponding mint. It might also include some metadata.
+
+```ts
+const t: Token = {
+  proofs: [...proofs],
+  mint: "https://minturl.com",
+  memo: "Hello world",
+};
+```
+
+## Encoding
+
+Token are usually encoded before they are transmitted. `cashu-ts` supports both Token V3 and Token V4 encoding.
+
+```ts
+const encodedV3 = getEncodedToken(t, { version: 3 });
+
+const encodedV4 = getEncodedToken(t, { version: 4 });
+// or
+const encodedV4 = getEncodedToken(t);
+```
+
+:::warning
+
+While `getEncodedToken` will default to V4 encoding in most cases, some proofs with older, non-hex keyset IDs can not be encoded to V4. In this case getEncodedToken will automatically fallback to V3 encoding.
+
+:::
+
+## Decoding
+
+Decoding a Token string back to the **Token** object can be done using the `getDecodedToken` utility.
+
+```ts
+const decoded = getDecodedToken(tokenString);
+```