* Deprecate ec2_vpc module
The deprecation of ec2_vpc module has been discussed for
2 years and is causing duplication of effort as changes
are implemented for ec2_vpc rather than for the newer
alternatives
* Improve module deprecation documentation
Update the developing modules documentation with the latest
instructions on how to deprecate a module.
* developing_modules.rst is now in dev_guide, sync changes and delete the old version
* Cleaner RST & formatted code
* Tidyup roadmaps
* Link to repomerge
* Pull in abadger's fixes From https://github.com/ansible/ansible/compare/docs-code-block-fixes?expand=1
* Clean docsite/rst (apart from ROADMAP
