Surrounding lines to filtered events

Thank you for awslogs! It's a great tool.

However, the thing I pretty much always end up doing with it is performing a search, then copy/pasting some timestamps to form a window surrounding the search hit, then doing another query to get a bunch of lines. It would be really cool if `awslogs` had an option like `grep`'s `-C/--context` option that could show me a bunch of surrounding lines.

Thanks again!

Start at the awslogs command-line query and filtering entry point, then trace how filtered events are selected and displayed. Compare the requested behavior with grep's -C/--context option and verify the result against searches that have matching events; done means the command can show the requested surrounding lines without manually forming a timestamp window.

Written by the indexing model from the issue text.