(no-ticket) TAG New Joiners instructions (sio2project#88)

* Added simple GUIDE for new joiners

GUIDE.md

@@ -0,0 +1,115 @@
+# TAG - New Joiner onboarding - 2022 edition
+A few useful tips for TAG new joiners. SIO2Project is a growing project mainly maintained by the TAG team.
+The project's architecture was previously held on self-served platforms such as Gerrit, Hudson etc.
+By the end of academic year 2022 most of the architecture was moved to GitHub.
+
+* Gerrit (code review) -> GitHub code review
+* Hudson (automated jobs) -> GitHub Actions
+
+There are still some deployment jobs left on Hudson, but GitHub Secrets can be a bright future for OIOIOI.
+All the tickets raised during development are still in Jira, and it is not intended to change that.
+
+## Prepare your development environment
+First things first - the best way to run OIOIOI (web service of SIO2Project) is to use Docker.
+Any other installation method described in documentation does not work, so you just need to follow
+instructions in `README.rst`. Using `docker-compose` works only on Linux and MacOS - Windows is not supported.
+
+Install Docker and docker-compose on your computer - if you don't know how just type in `How to install Docker on XZY`,
+where `XYZ` is your operating system. Do the same for `docker-compose`.
+
+Remember to add user to docker group
+```bash
+sudo groupadd docker
+gpasswd -a $USER docker
+newgrp docker
+```
+
+All the commands below are being run in `oioioi` directory (main directory of the repository).
+In order to use `easy_toolbox.py` alternative method, check python package requirements in `easy_toolbox.py`. 
+
+To build OIOIOI image run 
+```bash
+OIOIOI_UID=$(id -u) docker-compose -f docker-compose-dev.yml -f extra/docker/docker-compose-dev-noserver.yml build
+```
+or
+```bash
+./easy_toolbox.py build  
+```
+
+Set your containers up and running
+```bash
+OIOIOI_UID=$(id -u) docker-compose -f docker-compose-dev.yml -f extra/docker/docker-compose-dev-noserver.yml up -d
+```
+or
+```bash
+./easy_toolbox.py up
+```
+
+Wait some time for the migration to finish (no more than a few minutes).
+
+Run your web service
+```bash
+OIOIOI_UID=$(id -u) docker-compose -f docker-compose-dev.yml -f extra/docker/docker-compose-dev-noserver.yml exec web python3 manage.py runserver 0.0.0.0:8000
+```
+or
+```bash
+./easy_toolbox.py run
+```
+
+Now visit `localhost:8000` and start exploring OIOIOI.
+
+## Run unit tests
+In order to run unit tests Docker installation is required.
+To do it just run
+```bash
+docker-compose -f docker-compose-dev.yml -f extra/docker/docker-compose-dev-noserver.yml exec "web" ../oioioi/test.sh
+```
+or
+```bash
+./easy_toolbox.py test
+```
+
+## Run e2e tests
+In order to run Cypress tests a few more steps are required.
+- Clear the database
+- Create superuser (admin, admin)
+- Run the service
+- Run the tests
+
+All of these steps can be done by running
+```bash
+./easy_toolbox.py flush-db && ./easy_toolbox.py add-superuser && ./easy_toolbox.py cypress-apply-settings && ./easy_toolbox.py run
+```
+and (in new terminal)
+```bash
+./test_cypress.sh [-g]
+```
+
+Normally these tests are being run on GitHub Actions as a nightly test workflow, but in the future it is intended
+to create separate testing environment for Cypress using SQLite database and data from fixtures files.
+
+## Contributing
+In order to contribute to OIOIOI just `fork` the repository, clone the copy, make changes as in normal repository
+and when the change is ready, create a push request to master branch of `sio2project/oioioi`.
+
+## GitHub Actions
+As mentioned above GitHub Actions replaced most of the Hudson jobs. Right now the available workflows are:
+- Unit tests
+- Nightly tests (unit tests with testes marked as 'slow')
+- Bi-Nightly Cypress e2e tests
+- Documentation generator
+- Transifex translations downloader
+- Transifex translations uploader
+
+## Deployment
+No changes can be seen on `szkopul.edu.pl` without deployment. 
+@twalen is responsible for conducting the deployments, and they are usually done during
+maintenance window (see `szkopul.edu.pl` main page for details).
+
+During deployment translation files are being uploaded and downloaded. The translation manager is 
+[Transifex](https://www.transifex.com/sio2project/sio2project/dashboard/). When you add localized text 
+to OIOIOI it is uploaded to Transifex with GitHub Action and later, when translated, downloaded,
+compiled and saved to the codebase. (Both of these jobs need to be run manually).
+
+## Ticketing
+All the ticketing is still done via [Jira](https://jira.sio2project.mimuw.edu.pl/).