translation: Update index.md (krahets#1548)

* translation: Update index.md

refined some parts of the sentences.

changed 'in' to 'on' as it conveys a sense of movement along a path

* translation: Update index.md

changed some words per Thomas's suggestions.

en/docs/chapter_searching/index.md

@@ -4,6 +4,6 @@
 
 !!! abstract
 
-    Searching is an unknown adventure, where we may need to traverse every corner of a mysterious space, or perhaps quickly pinpoint our target.
+    Searching is an adventure into the unknown; where we may need to traverse every corner of a mysterious space, or perhaps we’ll quickly locate our target.
 
-    In this journey of discovery, each exploration may yield an unexpected answer.
+    On this journey of discovery, each exploration may end up with an unexpected answer.