Minor grammatical correction
Cookbook article about custom route loaders
Processed feedback by @lazyhammer and @WouterJ
Adding description of how to test a command which expects user input
Added use cases and explained the loader resolver
Minor improvements suggested by @WouterJ
Added some references to bundles using route loaders
Adding a database cookbook with the topics unit tests and config_test.yml covered
add note on service parameters regarding ScopeWideningInjectionException
Refactoring example code for the dialog helper command test
fix backticks with double backticks
Making some minor bugfixes to the testing/database cookbook. Added different code examples
remove unnecessary text
Wrap all yml strings containing "@" with quotes in order to render the
syntax highlighting correctly
Wrap all YAML strings starting with "@" with quotes

Without quotes, the parser doesn't render the syntax highlighting correctly
Issue #2378. Minor additions. Implemented suggestions by WouterJ.
Wrap all YAML parameter % uses with quotes

Without quotes, the parser doesn't render the syntax highlighting correctly
Remove useless spaces in the YAML code blocks
Reword sentence to make clear what should be read
Removed note, it's important information!