document upload procedure

doc/source/_static/fex-email.png

doc/source/_static/fex-upload.png

doc/source/_static/gitlab-pipelines-delete-file.png

doc/source/_static/gitlab-pipelines.png

doc/source/_static/job-done-with-filename.png

doc/source/_static/job-done-with-url.png

doc/source/_static/trigger-job-with-filename.png

doc/source/_static/trigger-job-with-url.png

doc/source/index.rst

doc/source/web_admin.rst