Add section on test environment
Add section on custom helpers
describe YAML frontmatter
Fix minor formatting errors
document $INCLUDE as obsolete
Change documentation of negative error
Move test environment and custom helpers down
indent copyright and frontmatter sections
better description of the async calls between a promise
and the functions in its `.then`
Correct Early Error example: don't throw a string
CONSOLE-RUNNER: split runner doc into new file
add troubleshooting section
add a table showing which print handle to use when
running async tests through test262.py runner
@anba contributed information about async tests in
SpiderMonkey and JavaScriptCore
add a section on requirements for using console test runner test262.py
add a section on asynchronous tests
add subsection to authoring guidelines with suggestion for test names