[docs] Add NOT to REACT_APP_SECRET_CODE

Fixes #5676

docusaurus/docs/adding-custom-environment-variables.md

@@ -19,7 +19,7 @@ default you will have `NODE_ENV` defined for you, and any other environment vari
 > Note: You must create custom environment variables beginning with `REACT_APP_`. Any other variables except `NODE_ENV` will be ignored to avoid accidentally [exposing a private key on the machine that could have the same name](https://github.com/facebook/create-react-app/issues/865#issuecomment-252199527). Changing any environment variables will require you to restart the development server if it is running.
 
 These environment variables will be defined for you on `process.env`. For example, having an environment
-variable named `REACT_APP_SECRET_CODE` will be exposed in your JS as `process.env.REACT_APP_SECRET_CODE`.
+variable named `REACT_APP_NOT_SECRET_CODE` will be exposed in your JS as `process.env.REACT_APP_NOT_SECRET_CODE`.
 
 There is also a special built-in environment variable called `NODE_ENV`. You can read it from `process.env.NODE_ENV`. When you run `npm start`, it is always equal to `'development'`, when you run `npm test` it is always equal to `'test'`, and when you run `npm run build` to make a production bundle, it is always equal to `'production'`. **You cannot override `NODE_ENV` manually.** This prevents developers from accidentally deploying a slow development build to production.
 
@@ -35,14 +35,14 @@ render() {
     <div>
       <small>You are running this application in <b>{process.env.NODE_ENV}</b> mode.</small>
       <form>
-        <input type="hidden" defaultValue={process.env.REACT_APP_SECRET_CODE} />
+        <input type="hidden" defaultValue={process.env.REACT_APP_NOT_SECRET_CODE} />
       </form>
     </div>
   );
 }
 ```
 
-During the build, `process.env.REACT_APP_SECRET_CODE` will be replaced with the current value of the `REACT_APP_SECRET_CODE` environment variable. Remember that the `NODE_ENV` variable will be set for you automatically.
+During the build, `process.env.REACT_APP_NOT_SECRET_CODE` will be replaced with the current value of the `REACT_APP_NOT_SECRET_CODE` environment variable. Remember that the `NODE_ENV` variable will be set for you automatically.
 
 When you load the app in the browser and inspect the `<input>`, you will see its value set to `abcdef`, and the bold text will show the environment provided when using `npm start`:
 
@@ -53,7 +53,7 @@ When you load the app in the browser and inspect the `<input>`, you will see its
 </div>
 ```
 
-The above form is looking for a variable called `REACT_APP_SECRET_CODE` from the environment. In order to consume this
+The above form is looking for a variable called `REACT_APP_NOT_SECRET_CODE` from the environment. In order to consume this
 value, we need to have it defined in the environment. This can be done using two ways: either in your shell or in
 a `.env` file. Both of these ways are described in the next few sections.
 
@@ -90,21 +90,21 @@ life of the shell session.
 ### Windows (cmd.exe)
 
 ```cmd
-set "REACT_APP_SECRET_CODE=abcdef" && npm start
+set "REACT_APP_NOT_SECRET_CODE=abcdef" && npm start
 ```
 
 (Note: Quotes around the variable assignment are required to avoid a trailing whitespace.)
 
 ### Windows (Powershell)
 
 ```Powershell
-($env:REACT_APP_SECRET_CODE = "abcdef") -and (npm start)
+($env:REACT_APP_NOT_SECRET_CODE = "abcdef") -and (npm start)
 ```
 
 ### Linux, macOS (Bash)
 
 ```bash
-REACT_APP_SECRET_CODE=abcdef npm start
+REACT_APP_NOT_SECRET_CODE=abcdef npm start
 ```
 
 ## Adding Development Environment Variables In `.env`
@@ -114,7 +114,7 @@ REACT_APP_SECRET_CODE=abcdef npm start
 To define permanent environment variables, create a file called `.env` in the root of your project:
 
 ```
-REACT_APP_SECRET_CODE=abcdef
+REACT_APP_NOT_SECRET_CODE=abcdef
 ```
 
 > Note: You must create custom environment variables beginning with `REACT_APP_`. Any other variables except `NODE_ENV` will be ignored to avoid [accidentally exposing a private key on the machine that could have the same name](https://github.com/facebook/create-react-app/issues/865#issuecomment-252199527). Changing any environment variables will require you to restart the development server if it is running.