fix(docs; config): update Gradient signup link in README and app config

Author: MRColorR

README.md

@@ -173,7 +173,7 @@ Register an account on the app's sites clicking each apps' names in the followin
 | Go to [SPEEDSHARE](https://speedshare.app/?ref=mindlessnerd) | :white_check_mark: | :x: | Unlimited | 1 |
 | Go to [GRASS](https://app.getgrass.io/register/?referralCode=qyvJmxgNUhcLo2f) | :white_check_mark: | :x: | Unlimited | 1 |
 | Go to [PACKETSHARE](https://www.packetshare.io/?code=A260871CFD822E35) | :white_check_mark: | :x: | Unlimited | 1 |
-| Go to [GRADIENT](https://app.gradient.network/signup?code=2WEG9X) | :white_check_mark: | :x: | Unlimited | 1 |
+| Go to [GRADIENT](https://app.gradient.network/signup?code=9WOBKP) using code `9WOBKP` or `2WEG9X`| :white_check_mark: | :x: | Unlimited | 1 |
 | Go to [MYSTNODE](https://mystnodes.co/?referral_code=Tc7RaS7Fm12K3Xun6mlU9q9hbnjojjl9aRBW8ZA9) | :white_check_mark: | :white_check_mark: |Unlimited|Unlimited|
 | Go to [DAWN](https://dawninternet.com?code=xo23vynw) using code: `xo23vynw` | :white_check_mark: | :x: | Unlimited | 1 |
 | Go to [TENEO](https://dashboard.teneo.pro/?code=qPgLn) using code: `qPgLn` | :white_check_mark: | :x: | Unlimited | 1 |

config/app-config.json

@@ -387,7 +387,7 @@
     {
       "name": "GRADIENT",
       "dashboard": "https://app.gradient.network/dashboard",
-      "link": "https://app.gradient.network/signup?code=2WEG9X",
+      "link": "https://app.gradient.network/signup?code=9WOBKP",
       "compose_config": {
         "container_name": "${DEVICE_NAME}_gradient",
         "hostname": "${DEVICE_NAME}_gradient",