Update ENVS.md (#2765)

Update reCAPTURE ENV to add Blockscout doc reference and update variable example from <your-secret> to <your-site-key> avoid confusion between SITE and SECRET keys.

docs/ENVS.md

@@ -911,9 +911,9 @@ This feature enables Blockscout Merits program. It requires that the [My account
 
 ### Google ReCaptcha
 
-For obtaining the variable values, please refer to the [reCAPTCHA documentation](https://developers.google.com/recaptcha). Please note that we currently support only **reCAPTCHA v2 in invisible mode**, read more [here](https://developers.google.com/recaptcha/docs/versions#recaptcha_v2_invisible_recaptcha_badge).
+To obtain the variable values, please refer to the [reCAPTCHA documentation](https://developers.google.com/recaptcha) and check the [Blockscout reCAPTCHA config docs](https://docs.blockscout.com/setup/configuration-options/recaptcha). Please note that we currently support only **reCAPTCHA v2 in invisible mode**, read more [here](https://developers.google.com/recaptcha/docs/versions#recaptcha_v2_invisible_recaptcha_badge).
 
 | Variable | Type| Description | Compulsoriness  | Default value | Example value | Version |
 | --- | --- | --- | --- | --- | --- | --- |
 | NEXT_PUBLIC_RE_CAPTCHA_V3_APP_SITE_KEY | `string` | **DEPRECATED** Google reCAPTCHA v3 site key | - | - | `<your-secret>` | v1.36.x |
-| NEXT_PUBLIC_RE_CAPTCHA_APP_SITE_KEY | `string` | Google reCAPTCHA v2 site key | - | - | `<your-secret>` | v1.0.x+ |
\ No newline at end of file
+| NEXT_PUBLIC_RE_CAPTCHA_APP_SITE_KEY | `string` | Google reCAPTCHA v2 site key | - | - | `<your-site-key>` | v1.0.x+ |