docs: remove references to deprecated proxy config variable (#1902)

website/docs/how-to/how-to-use-custom-strategies.md

@@ -16,7 +16,6 @@ In this example we want to define an activation strategy offers a scheduled rele
 
    ![A strategy creation form. It has fields labeled "strategy name" — "TimeStamp" — and "description" — "activate toggle after a given timestamp". It also has fields for a parameter named "enableAfter". The parameter is of type "string" and the parameter description is "Expected format: YYYY-MM-DD HH:MM". The parameter is required.](/img/timestamp_create_strategy.png)
 
-
 ## Step 2: Apply your custom strategy to a feature toggle {#step-2}
 
 **Navigate to your feature toggle** and **apply the strategy** you just created.
@@ -27,8 +26,8 @@ In this example we want to define an activation strategy offers a scheduled rele
 
 The steps to implement a custom strategy for your client depend on the kind of client SDK you're using:
 
-- if you're using a server-side client SDK, follow the steps in [option A](#step-3-a "Step 3 option A: implement the strategy for a server-side client SDK").
-- if you're using a front-end client SDK ([Android](../sdks/android-proxy.md), [JavaScript](../sdks/proxy-javascript.md), [React](../sdks/proxy-react.md), [iOS](../sdks/proxy-ios.md)), follow the steps in [option B](#step-3-b "Step 3 option B: implementing the strategy for a front-end client SDK")
+- if you're using a server-side client SDK, follow the steps in [option A](#step-3-a 'Step 3 option A: implement the strategy for a server-side client SDK').
+- if you're using a front-end client SDK ([Android](../sdks/android-proxy.md), [JavaScript](../sdks/proxy-javascript.md), [React](../sdks/proxy-react.md), [iOS](../sdks/proxy-ios.md)), follow the steps in [option B](#step-3-b 'Step 3 option B: implementing the strategy for a front-end client SDK')
 
 ### Option A: Implement the strategy for a server-side client SDK {#step-3-a}
 
@@ -78,12 +77,12 @@ The steps to implement a custom strategy for your client depend on the kind of c
        console.log(isEnabled('demo.TimeStampRollout'));
      }, 1000);
    });
-
    ```
 
 ### Option B: Implement the strategy for a front-end client SDK {#step-3-b}
 
 Front-end client SDKs don't evaluate strategies directly, so you need to implement the **custom strategy in the [Unleash Proxy](../sdks/unleash-proxy.md)**. Depending on how you run the Unleash Proxy, follow one of the below series of steps:
+
 - If you're running the Unleash Proxy as a Docker container, refer to the [steps for using a containerized Proxy](#step-3-b-docker).
 - If you're using the Unleash Proxy via Node.js, refer to the [steps for using custom strategies via Node.js](#step-3-b-node).
 
@@ -121,7 +120,7 @@ Strategies are stored in separate JavaScript files and loaded into the container
 
    ```shell
    docker run --name unleash-proxy --pull=always \
-       -e UNLEASH_PROXY_SECRETS=some-secret \
+       -e UNLEASH_PROXY_CLIENT_KEYS=some-secret \
        -e UNLEASH_URL='http://unleash:4242/api/' \
        -e UNLEASH_API_TOKEN=${API_TOKEN} \
        # highlight-start
@@ -177,11 +176,12 @@ The Unleash Proxy accepts a `customStrategies` property as part of its initializ
 
    const app = createApp({
      unleashUrl: 'https://app.unleash-hosted.com/demo/api/',
-       unleashApiToken: '*:default.56907a2fa53c1d16101d509a10b78e36190b0f918d9f122d',
-       proxySecrets: ['proxy-secret', 'another-proxy-secret', 's1'],
+     unleashApiToken:
+       '*:default.56907a2fa53c1d16101d509a10b78e36190b0f918d9f122d',
+     clientKeys: ['proxy-secret', 'another-proxy-secret', 's1'],
      refreshInterval: 1000,
      // highlight-next-line
-       customStrategies: [new TimeStampStrategy()]
+     customStrategies: [new TimeStampStrategy()],
    });
 
    app.listen(port, () =>

website/docs/user_guide/quickstart.md

@@ -282,7 +282,7 @@ Follow steps outlined in the [Run Unleash with Docker](#run-unleash-with-docker)
 
    ```sh
    docker run \
-     -e UNLEASH_PROXY_SECRETS=some-secret \
+     -e UNLEASH_PROXY_CLIENT_KEYS=some-secret \
      -e UNLEASH_URL='http://unleash:4242/api/' \
      -e UNLEASH_API_TOKEN='${API_KEY}' \
      -p 3000:3000 \