Add a manual page

app/main/routes.py

app/static/images/manual/add-corpus-file.png

app/static/images/manual/corpus.png

app/static/images/manual/create-a-corpus.png

app/static/images/manual/dashboard.png

app/static/images/manual/job.png

app/static/images/manual/registration-and-log-in.png

app/static/images/manual/services.png

app/templates/_navbar.html.j2

app/templates/_sidenav.html.j2

app/templates/corpora/analyse_corpus.concordance.html.j2

app/templates/corpora/analyse_corpus.html.j2

app/templates/main/manual/_01_introduction.html.j2

...templates/main/manual/_02_registration_and_log_in.html.j2

app/templates/main/manual/_03_dashboard.html.j2

app/templates/main/manual/_06_services.html.j2

...n/manual/_07_a_closer_look_at_the_corpus_analysis.html.j2

app/templates/main/manual/_08_cqp_query_language.html.j2

app/templates/main/user_manual.html.j2