[C++][Docs] Provide row conversion example for dynamic schemas

[asfimport]

Short version: Given a way to convert a vector of rows and a schema to a RecordBatch, we can derive methods for efficiently converting a vector of rows to a Table or even an iterator of rows to a Record Batch Reader. Similarly, we could go the other way: given a way to convert a RecordBatch to a vector of rows, we can derive methods for converting from Tables or RBRs.

Long version: https://docs.google.com/document/d/174tldmQLMCvOtjxGtFPeoLBefyE1x26_xntwfSzDXFA/edit?usp=sharing

Reporter: Will Jones / @wjones127
Assignee: Will Jones / @wjones127

Related issues:

• [C++] Document VisitArrayInline and type traits (is related to)

PRs and other links:

• GitHub Pull Request #12775

_{Note: This issue was originally created as ARROW-16006. Please see the migration documentation for further details.}

[asfimport]

David Li / @lidavidm:
Issue resolved by pull request 12775
#12775