No mentioning of limitations of EXCHANGE PARTITION when it comes to Index IDs

[mjonss]

Change Request

Please answer the following questions before submitting your issue. Thanks!

1. Describe what you find is inappropriate or missing in the existing docs.
   In partition can't exchange when table schema is same  tidb#50906 there is an issue for EXCHANGE PARTITION, when the table structures looks the same, but internally they have different index ids.

2. Describe your suggestion or addition.
   Add a paragraph about EXCHANGE PARTITION and table structures, including the workaround CREATE TABLE tnp LIKE partitioned_table; alter table tnp remove partitioning; to get exact the same indexes etc.

3. Provide some reference materials (such as documents and websites) if you could.
   https://docs.pingcap.com/tidb/stable/partitioned-table#partition-management

[Oreoxmt]

@YangKeao Could you please help take a look at this issue and submit a PR to update the document if needed?