Fix wonky section numbers.

Complete lab 12

WIP lab 12.

Minor tweak to code font style

Remove heavy plus char that is actually tiny in noto-sans.

Improve some bits that caused problems for students.

Move files into correct location

s/JDBC/JDBI/

req.param -> ctx.path

Release fixes

Add generated saleId back to sale. Add missing @Override.

Fix missing " in nav menu

Release lab 11

Embiggened the warning icons.

Complete lab 11

Add HTTP auth to reference

Release updated version

Final tweaks after working through lab myself.

Fix theme/mode

Fix nav menu and formatting.

Fix typo in formatter code.

Add a quick section on totals

Add clarification about passing product to the buyProduct function.

Typo fixes.

Forgot to add section on formatting numbers - fixed.

Complete lab 10

Make + sign in keys macro clearer

Improve sections that students had problems with.

Update build.gradle based on recent problems that students have had

Making warning icon darker (poor contrast in light theme).