Fix a typo in the cat shards API docs (#38536)

docs/reference/cat/shards.asciidoc

@@ -56,7 +56,7 @@ twitter 0 p STARTED 3014 31.1mb 192.168.56.10 H5dfFeA
 [[relocation]]
 === Relocation
 
-Let's say you've checked your health and you see a relocating
+Let's say you've checked your health and you see relocating
 shards.  Where are they from and where are they going?
 
 [source,js]