fix misspelling in CONTRIBUTING.md

Author: x13machine

docs/CONTRIBUTING.md

@@ -26,7 +26,7 @@ The following table lists the ticket type labels we use when there is work to be
 |:----------------------------------|:-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
 |L0 - security                      |A security vulnerability within the Marked library is discovered.                                                                                                                   |
 |L1 - broken                        |Valid usage results in incorrect output compared to [supported specifications](#/README.md#specifications) OR causes marked to crash AND there is no known workaround for the issue. |
-|L2 - annoying                      |Similar to L1 - broken only there is a known workaround avaialable for the issue.                                                                                                   |
+|L2 - annoying                      |Similar to L1 - broken only there is a known workaround available for the issue.                                                                                                   |
 |RR - refactor and re-engineer      |Results in an improvement to developers using Marked (improved readability) or end-users (faster performance) or both.                                                              |
 |NFS - new feature (spec related)   |A capability Marked does not currently provide but is in one of the [supported specifications](#/README.md#specifications)                                                           |
 |NFU - new feature (user requested) |A capability Marked does not currently provide but has been requested by users of Marked.                                                                                           |