Docs: Index page with all SQL functions (#12771)

* list of all functions

* add function names to spelling file

website/.spelling

@@ -2019,3 +2019,85 @@ Golang
 multiValueHandling
 _n_
 100TB
+ - ../docs/querying/sql-functions.md
+ANY_VALUE 
+APPROX_COUNT_DISTINCT_DS_HLL 
+APPROX_COUNT_DISTINCT_DS_THETA 
+APPROX_QUANTILE_DS 
+APPROX_QUANTILE_FIXED_BUCKETS 
+ARRAY_CONCAT_AGG 
+BIT_AND 
+BIT_OR 
+BIT_XOR 
+BITWISE_AND 
+BITWISE_COMPLEMENT 
+BITWISE_CONVERT_DOUBLE_TO_LONG_BITS 
+BITWISE_CONVERT_LONG_BITS_TO_DOUBLE 
+BITWISE_OR 
+BITWISE_SHIFT_LEFT 
+BITWISE_SHIFT_RIGHT 
+BITWISE_XOR 
+BLOOM_FILTER 
+BTRIM 
+CHAR_LENGTH 
+CHARACTER_LENGTH 
+CURRENT_DATE 
+CURRENT_TIMESTAMP 
+DATE_TRUNC 
+DS_CDF 
+DS_GET_QUANTILE 
+DS_GET_QUANTILES 
+DS_HISTOGRAM 
+DS_HLL 
+DS_QUANTILE_SUMMARY 
+DS_QUANTILES_SKETCH 
+DS_RANK 
+DS_THETA 
+EARLIEST_BY 
+_e_
+HLL_SKETCH_ESTIMATE 
+HLL_SKETCH_ESTIMATE_WITH_ERROR_BOUNDS 
+HLL_SKETCH_TO_STRING 
+HLL_SKETCH_UNION 
+LATEST_BY 
+base-10
+MV_APPEND 
+MV_CONCAT 
+MV_CONTAINS 
+MV_FILTER_NONE 
+MV_FILTER_ONLY 
+MV_LENGTH 
+MV_OFFSET 
+MV_OFFSET_OF 
+MV_ORDINAL 
+MV_ORDINAL_OF 
+MV_OVERLAP 
+MV_PREPEND 
+MV_SLICE 
+MV_TO_STRING 
+NULLIF 
+_n_th
+STDDEV_POP 
+STDDEV_SAMP 
+STRING_FORMAT 
+STRING_TO_MV 
+SUBSTR 
+TDIGEST_GENERATE_SKETCH 
+TDIGEST_QUANTILE 
+TEXTCAT 
+THETA_SKETCH_ESTIMATE 
+THETA_SKETCH_ESTIMATE_WITH_ERROR_BOUNDS 
+THETA_SKETCH_INTERSECT 
+THETA_SKETCH_NOT 
+THETA_SKETCH_UNION 
+TIME_CEIL 
+TIME_EXTRACT 
+TIME_FLOOR 
+TIME_FORMAT 
+TIME_IN_INTERVAL 
+TIMESTAMP_TO_MILLIS 
+TIMESTAMPADD 
+TIMESTAMPDIFF 
+TRUNC 
+VAR_POP 
+VAR_SAMP

website/sidebars.json

@@ -76,6 +76,7 @@
           "querying/sql-scalar",
           "querying/sql-aggregations",
           "querying/sql-multivalue-string-functions",
+          "querying/sql-functions",
           "querying/sql-api",
           "querying/sql-jdbc",
           "querying/sql-query-context",