[Chapel Merge] Add noinit technote

Branch: refs/heads/master
Revision: 746a3a9
Author: mppf
Log Message:

Merge pull request #16526 from mppf/doc-updates-18

Add noinit technote

Follow-up to PR #16064.

The 1.23 release includes a very basic and restricted version of noinit
because we were able to agree on the behavior of that case.

The noinit feature is discussed in #15703 and #8792. The future work is
discussed in #16172, #16173.

Reviewed by @lydia-duncan - thanks!

Modified Files:
A doc/rst/technotes/noinit.rst
M doc/rst/technotes/index.rst

Compare: https://github.com/chapel-lang/chapel/compare/deb2c2786898...746a3a974734