release v0.8.0

RE #8: Feature/auto generated toc (#9)

fixed the `copy-from` script and the `rename-index` script

fixed a minor Bash multiline command error

readme: general use-case: updated the ref to one of the dependency actions

fixed some minor typos

workflows: tests: fixed double checks (on pull request and on push)

bumped to version 0.7.0

updated readme (formatting and typos)

tests: added two new tests [details below]

tests: switched from custom to `unittest`

tests: simple: added document title check

tests: refactored the testing suite [details below]

pandoc script: added some helper switches for turning off some of functionalities (for testing purposes)

pandoc script: added automatic title scraping [details below]