docs: fix wording in subscribe steps (#858)

Author: nfrankel

website/docs/general/subscribe-guide.md

@@ -16,8 +16,8 @@ During the process of using Apache APISIX, if there has any problems, suggestion
 
 2. Receive and reply the confirmation e-mail. After Step 1, you will receive a confirmation e-mail from dev-help@apisix.apache.org (if you can not receive that, please check “RSS feeds”, “junk e-mail” or other items). Reply that e-mail directly or click the link in e-mail to reply, with any subjects or contents.
 
-3. Receive the Welcome e-mail. After finishing the two steps above, an e-mail with the subject of WELCOME to dev@apisix.apache.org will be sent to your e-mail address. Until now, you have succeeded in subscribing Apache APISIX mailing-list.
+3. Receive the Welcome e-mail. After finishing the two steps above, an e-mail with the subject of WELCOME to dev@apisix.apache.org will be sent to your e-mail address. Congrats, you have succeeded in subscribing Apache APISIX mailing-list.
 
-4. Until now, you can interact with community by your subscribed email or track email conversations by Archived email list.
+4. At this stage, you can interact with community by your subscribed email or track email conversations by Archived email list.
 
 5. To view the Archived email lists, check out [history mailing-list](https://lists.apache.org/list.html?apisix.apache.org).