Update tutorial-discovering.asciidoc (#76976)

* Update tutorial-discovering.asciidoc

Adds alt text to images in doc.

* Update docs/getting-started/tutorial-discovering.asciidoc

* Update docs/getting-started/tutorial-discovering.asciidoc

Co-authored-by: Kaarina Tungseth <kaarina.tungseth@elastic.co>

docs/getting-started/tutorial-discovering.asciidoc

@@ -21,7 +21,7 @@ The search returns all account numbers between zero and 99 with balances in
 excess of 47,500. Results appear for account numbers 8, 32, 78, 85, and 97.
 +
 [role="screenshot"]
-image::images/tutorial-discover-2.png[]
+image::images/tutorial-discover-2.png[Image showing the search results for account numbers between zero and 99, with balances in excess of 47,500]
 +
 . Hover over the list of *Available fields*, then
 click *Add* next to each field you want include in the table.
@@ -30,6 +30,6 @@ For example, when you add the `account_number` field, the display changes to a l
 account numbers.
 +
 [role="screenshot"]
-image::images/tutorial-discover-3.png[]
+image::images/tutorial-discover-3.png[Image showing a dropdown with five account numbers, which match the previous query for account balance]
 
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