Improve PgBinOper docs (#916)

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Author: Huliiiiii

src/extension/postgres/mod.rs

@@ -23,30 +23,50 @@ pub(crate) mod types;
 pub enum PgBinOper {
     ILike,
     NotILike,
+    /// `@@`. Full-text search match
     Matches,
+    /// `@>`. Contains operator - checks if left operand contains right operand (arrays, JSON)
     Contains,
+    /// `<@`. Contained operator - checks if left operand is contained by right operand (arrays, JSON)
     Contained,
+    /// `||`. String/Array concatenation operator
     Concatenate,
+    /// `&&`. Overlap operator - checks if arrays have any elements in common
     Overlap,
+    /// `%`. Text similarity operator,
+    /// requires `pg_trgm` extension
     Similarity,
+    /// `<%`. Word similarity operator,
+    /// requires `pg_trgm` extension
     WordSimilarity,
+    /// `<<%`. Strict word similarity operator,
+    /// requires `pg_trgm` extension
     StrictWordSimilarity,
+    /// `<->`. Similarity distance operator,
+    /// requires `pg_trgm` extension
     SimilarityDistance,
+    /// `<<->`. Word similarity distance operator,
+    /// requires `pg_trgm` extension
     WordSimilarityDistance,
+    /// `<<<->`. Strict word similarity distance operator,
+    /// requires `pg_trgm` extension
     StrictWordSimilarityDistance,
-    /// `->`. Retrieves JSON field as JSON value.
+    /// `->`. Retrieves JSON field as JSON value
     GetJsonField,
-    /// `->>`. Retrieves JSON field and casts it to an appropriate SQL type.
+    /// `->>`. Retrieves JSON field and casts it to text
     CastJsonField,
-    /// `~` Regex operator.
+    /// `~`. Regex operator, case sensitively
     Regex,
-    /// `~*`. Regex operator with case insensitive matching.
+    /// `~*`. Regex operator, case-insensitively
     RegexCaseInsensitive,
     #[cfg(feature = "postgres-vector")]
+    /// `<->`. L2 (Euclidean) distance operator
     EuclideanDistance,
     #[cfg(feature = "postgres-vector")]
+    /// `<#>`. Negative inner product operator
     NegativeInnerProduct,
     #[cfg(feature = "postgres-vector")]
+    /// `<=>`. Cosine distance operator
     CosineDistance,
 }