github: Fix job name

github: Add build on 'ubuntu-24.04' and fix 'tlmgr install' failure

github: No need to install 'wget' and 'xz-utils'

github: Fix main workflow by using 'ubuntu-22.04' image

Minor corrections to README

Use an empty context for docker/podman image building

Fix "make docker" by providing the required build context

Update README to briefly mention Docker/Podman

Update Makefile to build with docker/podman

Add Dockerfile to create the builder image

class: Explain why \ignorespaces is required for CJK abstract

class: Fix the default position of photo to be left

resume: Update to use the new abstract environment

class: Renew the abstract environment for the summary/objectives

resume: Update PDF