Minor doc fixups

docs/en/engines/table-engines/mergetree-family/mergetree.md

@@ -991,48 +991,39 @@ They can be used for prewhere optimization only if we enable `set allow_statisti
 
 ### Available Types of Column Statistics {#available-types-of-column-statistics}
 
-Names of statistics types are case-insensitive, i.e. both
-
-``` sql
-CREATE TABLE tab
-(
-a LowCardinality(Int64) STATISTICS(minmax)
-) [...]
-```
-and
-``` sql
-CREATE TABLE tab
-(
-a LowCardinality(Int64) STATISTICS(MiNmAx)
-) [...]
-```
-work.
-
 - `MinMax`
 
     The minimum and maximum column value which allows to estimate the selectivity of range filters on numeric columns.
 
+    Syntax: `minmax`
+
 - `TDigest`
 
     [TDigest](https://github.com/tdunning/t-digest) sketches which allow to compute approximate percentiles (e.g. the 90th percentile) for numeric columns.
 
+    Syntax: `tdigest`
+
 - `Uniq`
 
     [HyperLogLog](https://en.wikipedia.org/wiki/HyperLogLog) sketches which provide an estimation how many distinct values a column contains.
 
+    Syntax: `uniq`
+
 - `CountMin`
 
     [CountMin](https://en.wikipedia.org/wiki/Count%E2%80%93min_sketch) sketches which provide an approximate count of the frequency of each value in a column.
 
+    Syntax `countmin`
+
 
 ### Supported Data Types {#supported-data-types}
 
-|           | (U)Int* | Float* | Decimal(*) | Date* | Boolean | Enum* | (Fixed)String    |
-|-----------|---------|--------|------------|-------|---------|-------|------------------|
-| CountMin  | ✔       | ✔      | ✔          | ✔     | ✔       | ✔     | ✔                |
-| MinMax    | ✔       | ✔      | ✔          | ✔     | ✔       | ✔     | ✗                |
-| TDigest   | ✔       | ✔      | ✔          | ✔     | ✔       | ✔     | ✗                |
-| Uniq      | ✔       | ✔      | ✔          | ✔     | ✔       | ✔     | ✔                |
+|           | (U)Int*, Float*, Decimal(*), Date*, Boolean, Enum* | String or FixedString |
+|-----------|----------------------------------------------------|-----------------------|
+| CountMin  | ✔                                                  | ✔                     |
+| MinMax    | ✔                                                  | ✗                     |
+| TDigest   | ✔                                                  | ✗                     |
+| Uniq      | ✔                                                  | ✔                     |
 
 
 ### Supported Operations {#supported-operations}