jq: clarify json text input from stdin

pages/common/jq.md

@@ -18,10 +18,10 @@
 
 `jq .[0] {{file.json}}`
 
-- Output the value of a given key of the first element in a JSON from stdin:
+- Output the value of a given key of the first element in a JSON text from stdin:
 
 `cat {{file.json}} | jq .[0].{{key_name}}`
 
-- Output the value of a given key of each element in a JSON from stdin:
+- Output the value of a given key of each element in a JSON text from stdin:
 
 `cat {{file.json}} | jq 'map(.{{key_name}})'`