update system environment variables page

Author: petebacondarwin

src/content/docs/workers/wrangler/system-environment-variables.mdx

@@ -16,45 +16,66 @@ System environment variables are local environment variables that can change Wra
 3. Set the values in your shell environment. For example, if you are using Z shell, adding `export CLOUDFLARE_API_TOKEN=...` to your `~/.zshrc` file will set this token as part of your shell configuration.
 
 :::note
-
 To set different system environment variables for each environment, create files named `.env.<environment-name>`. When you use `wrangler <command> --env <environment-name>`, the corresponding environment-specific file will be loaded instead of the `.env` file, so the two files are not merged.
 :::
 
+:::note
+During local development, the values in `.env` files are also loaded into the `env` object in your Worker, so you can access them in your Worker code.
+
+For example, if you set `API_HOST="localhost:3000"` in your `.env` file, you can access it in your Worker like this:
+
+```js
+const apiHost = env.API_HOST;
+```
+
+See the [Environment variables and secrets](/workers/development-testing/environment-variables/) page for more information on how to use `.env` files in local development.
+:::
+
 ## Supported environment variables
 
 Wrangler supports the following environment variables:
 
 - `CLOUDFLARE_ACCOUNT_ID` <Type text="string" /> <MetaInfo text="optional" />
+
   - The [account ID](/fundamentals/account/find-account-and-zone-ids/) for the Workers related account.
 
 - `CLOUDFLARE_API_TOKEN` <Type text="string" /> <MetaInfo text="optional" />
+
   - The [API token](/fundamentals/api/get-started/create-token/) for your Cloudflare account, can be used for authentication for situations like CI/CD, and other automation.
 
 - `CLOUDFLARE_API_KEY` <Type text="string" /> <MetaInfo text="optional" />
+
   - The API key for your Cloudflare account, usually used for older authentication method with `CLOUDFLARE_EMAIL=`.
 
 - `CLOUDFLARE_EMAIL` <Type text="string" /> <MetaInfo text="optional" />
+
   - The email address associated with your Cloudflare account, usually used for older authentication method with `CLOUDFLARE_API_KEY=`.
 
 - `WRANGLER_SEND_METRICS` <Type text="string" /> <MetaInfo text="optional" />
+
   - Options for this are `true` and `false`. Defaults to `true`. Controls whether Wrangler can send anonymous usage data to Cloudflare for this project. You can learn more about this in our [data policy](https://github.com/cloudflare/workers-sdk/tree/main/packages/wrangler/telemetry.md).
 
 - `WRANGLER_HYPERDRIVE_LOCAL_CONNECTION_STRING_<BINDING_NAME>`<Type text="string" /> <MetaInfo text="optional" />
+
   - The [local connection string](/hyperdrive/configuration/local-development/) for your database to use in local development with [Hyperdrive](/hyperdrive/). For example, if the binding for your Hyperdrive is named `PROD_DB`, this would be `WRANGLER_HYPERDRIVE_LOCAL_CONNECTION_STRING_PROD_DB="postgres://user:[email protected]:5432/testdb"`. Each Hyperdrive is uniquely distinguished by the binding name.
 
 - `CLOUDFLARE_API_BASE_URL` <Type text="string" /> <MetaInfo text="optional" />
+
   - The default value is `"https://api.cloudflare.com/client/v4"`.
 
 - `WRANGLER_LOG` <Type text="string" /> <MetaInfo text="optional" />
+
   - Options for Logging levels are `"none"`, `"error"`, `"warn"`, `"info"`, `"log"` and `"debug"`. Levels are case-insensitive and default to `"log"`. If an invalid level is specified, Wrangler will fallback to the default. Logs can include requests to Cloudflare's API, any usage data being collected, and more verbose error logs.
 
 - `WRANGLER_LOG_PATH` <Type text="string" /> <MetaInfo text="optional" />
+
   - A file or directory path where Wrangler will write debug logs. If the path ends in `.log`, Wrangler will consider this the path to a file where all logs will be written. Otherwise, Wrangler will treat the path as a directory where it will write one or more log files using a timestamp for the filenames.
 
 - `FORCE_COLOR` <Type text="string" /> <MetaInfo text="optional" />
   - By setting this to `0`, you can disable Wrangler's colorised output, which makes it easier to read with some terminal setups. For example, `FORCE_COLOR=0`.
 
 * `WRANGLER_HTTPS_KEY_PATH` <Type text="string" /> <MetaInfo text="optional" />
+
   - Path to a custom HTTPS certificate key when running `wrangler dev`, to be used with `WRANGLER_HTTPS_CERT_PATH`.
 
 * `WRANGLER_HTTPS_CERT_PATH` <Type text="string" /> <MetaInfo text="optional" />