dev: Improved tests, wrote docs

.github/CONTRIBUTING.md

.github/FUNDING.yml

.github/ISSUE_TEMPLATE/config.yml

.github/workflows/php-cs-fixer.yml

.github/workflows/run-tests.yml

.gitlab/SECURITY.md

.gitlab/issue_templates/BUG.md

.gitlab/issue_templates/FEATURE_PROPOSAL.md

CHANGELOG.md

README.md

composer.json

config/pubmed-api.php

database/factories/ModelFactory.php

database/migrations/create_pubmed-api_table.php.stub

resources/views/.gitkeep

src/Commands/LaravelPubmedApiCommand.php

src/Contracts/PubmedApiInterface.php

src/LaravelPubmedApi.php

src/LaravelPubmedApiServiceProvider.php

tests/ExampleTest.php