Merge pull request #303 from supertokens/docs/changelog_migration_guide_fix

docs: fix migration guide in changelog to be consistent with node

Author: rishabhpoddar

CHANGELOG.md

@@ -107,12 +107,17 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 #### If you used the jwt feature of the session recipe
 
 1. Add `ExposeAccessTokenToFrontendInCookieBasedAuth: true` to the Session recipe config on the backend if you need to access the JWT on the frontend.
-2. On the frontend where you accessed the JWT before by: `(await Session.getAccessTokenPayloadSecurely()).jwt` update to:
+2. Choose a prop from the following list. We'll use `sub` in the code below, but you can replace it with another from the list if you used it in a custom access token payload.
+    - `sub`
+    - `iat`
+    - `exp`
+    - `sessionHandle`
+3. On the frontend where you accessed the JWT before by: `(await Session.getAccessTokenPayloadSecurely()).jwt` update to:
 
 ```tsx
 let jwt = null;
 const accessTokenPayload = await Session.getAccessTokenPayloadSecurely();
-if (accessTokenPayload.jwt === undefined) {
+if (accessTokenPayload.sub !== undefined) {
     jwt = await Session.getAccessToken();
 } else {
     // This branch is only required if there are valid access tokens created before the update
@@ -121,12 +126,12 @@ if (accessTokenPayload.jwt === undefined) {
 }
 ```
 
-3. On the backend if you accessed the JWT before by `session.GetAccessTokenPayload()["jwt"]` please update to:
+4. On the backend if you accessed the JWT before by `session.GetAccessTokenPayload()["jwt"]` please update to:
 
 ```go
 var jwt string
 accessTokenPayload := session.GetAccessTokenPayload();
-if (accessTokenPayload["jwt"] == nil) {
+if (accessTokenPayload["sub"] != nil) {
     jwt =  session.GetAccessToken();
 } else {
     // This branch is only required if there are valid access tokens created before the update