DOCSP-16534 fixed backticks (#107)

* fixed backticks

Author: kyuan-mongodb

source/fundamentals/indexes.txt

@@ -204,7 +204,7 @@ Multikey Indexes (Indexes on Array Fields)
 **Multikey indexes** are indexes that improve performance for queries that specify a field with an index that contains
 an array value. You can define a multikey index using the same syntax as a single field or compound index.
 
-The following example creates a compound, multikey index on the ``rated`, ``genres`` (an array of
+The following example creates a compound, multikey index on the ``rated``, ``genres`` (an array of
 Strings), and ``title`` fields:
 
 .. common-content-end
@@ -303,7 +303,7 @@ the geospatial data for inclusion, intersection, and proximity. For more informa
 To create a 2dsphere index, you must specify a field that contains only **GeoJSON objects**. For more details on this
 type, see the MongoDB server manual page on :manual:`GeoJSON objects </reference/geojson>`.
 
-The ``location.geo` field in following sample document from the ``theaters`` collection in the ``sample_mflix```
+The ``location.geo`` field in following sample document from the ``theaters`` collection in the ``sample_mflix``
 database is a GeoJSON Point object that describes the coordinates of the theater:
 
 .. code-block:: javascript