DOC-7215 -- Remove confusing wording

https://issues.couchbase.com/browse/DOC-7215

Author: ibsoln

modules/ROOT/pages/_partials/commons/common-indexing.adoc

@@ -58,7 +58,6 @@ The code to create the index will look something like this:
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 include::{snippet}[tag=query-index,indent=0]
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-<.> Where there are multiple expressions, the first becomes the primary key, the second the secondary key and so on.
 
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