docs(in-context): add info about the screenshot_visible_area_only option (#659)

Author: rohalskyy

src/content/docs/developer/capabilities/in-context.mdx

@@ -196,6 +196,14 @@ _jipt.push(['tag_only_visible_phrases', true]);
 
 When set to `true`, this parameter ensures the screenshot tagging feature only processes strings currently visible in the user's viewport. This is ideal for dynamic interfaces, like single-page applications that use modals or dialogs that cover other on-page content. Enabling this option prevents hidden strings from being tagged, resulting in cleaner screenshots and more accurate context for translators. Acceptable values: `true`, `false`.
 
+### Capture Visible Area Only
+
+```js
+_jipt.push(['screenshot_visible_area_only', true]);
+```
+
+When set to `true`, In-Context captures only the part of the page currently visible in the user's viewport instead of taking a full-page screenshot. This is useful for long pages or dynamic interfaces where you want the screenshot to reflect exactly what translators see on screen. Acceptable values: `true`, `false`.
+
 ## Optional Functions
 
 You can call various functions on the global `window.jipt` object to manage or customize In-Context in real time.