Replace URLs into the Ansible docsite with RST references, 2/2

[felixfontein]

Follow-up to #3281.

Currently contains #3302, will rebase once that's merged.

[felixfontein]

• https://ansible--3306.org.readthedocs.build/projects/ansible-core/3306/playbook_guide/playbooks_privilege_escalation.html#risks-of-becoming-an-unprivileged-user
• https://ansible--3306.org.readthedocs.build/projects/ansible-core/3306/dev_guide/developing_program_flow_modules.html#ansible-tmpdir
• https://ansible--3306.org.readthedocs.build/projects/ansible-core/3306/dev_guide/style_guide/#adding-links-to-module-and-plugin-options-and-return-values