docs: add a reference to @lancedb/lance in the docs (#1166)

We aren't yet ready to switch over the examples since almost all JS
examples rely on embeddings and we haven't yet ported those over.
However, this makes it possible for those that are interested to start
using `@lancedb/lancedb`

docs/src/js/interfaces/AddColumnsSql.md

@@ -0,0 +1,37 @@
+[@lancedb/lancedb](../README.md) / [Exports](../modules.md) / AddColumnsSql
+
+# Interface: AddColumnsSql
+
+A definition of a new column to add to a table.
+
+## Table of contents
+
+### Properties
+
+- [name](AddColumnsSql.md#name)
+- [valueSql](AddColumnsSql.md#valuesql)
+
+## Properties
+
+### name
+
+• **name**: `string`
+
+The name of the new column.
+
+#### Defined in
+
+native.d.ts:43
+
+___
+
+### valueSql
+
+• **valueSql**: `string`
+
+The values to populate the new column with, as a SQL expression.
+The expression can reference other columns in the table.
+
+#### Defined in
+
+native.d.ts:48