Add release process to development section of manual

[prckent]

Proposed changes

Move contents of wiki page to manual. A few minor edits + also change copyright date in example.

Once merged I will remove it from https://github.com/QMCPACK/qmcpack/wiki/Release-process

What type(s) of changes does this code introduce?

• Documentation or build script changes

Does this introduce a breaking change?

• No

What systems has this change been tested on?

None

Checklist

Update the following with an [x] where the items apply. If you're unsure about any of them, don't hesitate to ask. This is
simply a reminder of what we are going to look for before merging your code.

• • I have read the pull request guidance and develop docs
• • This PR is up to date with current the current state of 'develop'
• • Code added or changed in the PR has been clang-formatted
• • This PR adds tests to cover any new code, or to catch a bug that is being fixed
• • Documentation has been added (if appropriate)

[ye-luo]

Test this please