Correct statement in docs about query results returning either floats or histograms but not both. (#11880)

* Correct statement in docs about query results returning either floats or histograms but not both.

* Move documentation for range and instant vectors under their corresponding headings.

Signed-off-by: Charles Korn <charles.korn@grafana.com>

docs/querying/api.md

@@ -449,9 +449,7 @@ raw numbers.
 
 The keys `"histogram"` and `"histograms"` only show up if the experimental
 native histograms are present in the response. Their placeholder `<histogram>`
-is explained in detail in its own section below. Any one object will only have
-the `"value"`/`"values"` key or the `"histogram"`/`"histograms"` key, but not
-both.
+is explained in detail in its own section below. 
 
 ### Range vectors
 
@@ -469,6 +467,9 @@ Range vectors are returned as result type `matrix`. The corresponding
 ]
 ```
 
+Each series could have the `"values"` key, or the `"histograms"` key, or both. 
+For a given timestamp, there will only be one sample of either float or histogram type.
+
 ### Instant vectors
 
 Instant vectors are returned as result type `vector`. The corresponding
@@ -485,6 +486,8 @@ Instant vectors are returned as result type `vector`. The corresponding
 ]
 ```
 
+Each series could have the `"value"` key, or the `"histogram"` key, but not both.
+
 ### Scalars
 
 Scalar results are returned as result type `scalar`. The corresponding