docs: fix the two snippet imports Mint cannot resolve

Two pages imported PySchemaAddSetup under the alias SchemaAddSetup, and
Mint resolved only the first, failing `mint validate` on
management/table.mdx. Both pages now import it unaliased.

TsAddProgress was added to the generated tables snippets by hand in
lancedb/docs#243 and dropped by the next regeneration, leaving
ingestion/insert.mdx with a missing import. Its example is restored
unchanged as a test in docs/web-tests/ts/tables.test.ts, which checks
that the callback reports the finished write.

docs/web/feature-engineering/data-evolution.mdx

@@ -7,7 +7,7 @@ keywords: ["data evolution", "derived columns", "add_columns", "zero copy", "fea
 ---
 
 import {
-    PySchemaAddSetup as SchemaAddSetup,
+    PySchemaAddSetup,
     TsSchemaAddSetup as TsSchemaAddSetup,
     RsSchemaAddSetup as RsSchemaAddSetup,
     PyAddColumnsCalculated as AddColumnsCalculated,
@@ -34,7 +34,7 @@ In SQL this is [`ALTER TABLE ... ADD COLUMN ... AS`](/sql/ddl/table#computed-col
 
 <CodeGroup>
     <CodeBlock filename="Python" language="Python" icon="python">
-    {SchemaAddSetup}
+    {PySchemaAddSetup}
     </CodeBlock>
 
     <CodeBlock filename="TypeScript" language="TypeScript" icon="square-js">