Addition for MBLD scoring (#1079)

Co-authored-by: ohexter <116421789+ohexter@users.noreply.github.com>

wca-guidelines.md

@@ -119,6 +119,7 @@ To be more informative, each Guideline is classified using one of the following
 - 9b++) [ADDITION] Events other than those specified in [Regulation 9b](regulations:regulation:9b) may be held during a competition, but will be considered unofficial and therefore will not be included in the official results of the competition.
 - 9b3b+) [CLARIFICATION] The "Mean of 3" statistic does not affect the competitor's ranking in a "Best of 3" round (which is based on the best result). The WCA recognizes it outside of the competition format.
 - 9f1+) [EXAMPLE] If the timer displays 12.678 for an attempt, the original recorded time is 12.67 (drop any digit after a hundredth of a second). A judge may write the full-precision time on the score sheet (and keep the precision in the calculation of penalties), as long as the score taker truncates it for the official results.
+- 9f2+) [ADDITION] For 3x3x3 Multi-Blind, the judge should record the number of puzzles solved, the number of puzzles attempted, and the final time. For example, if the competitor solves 3 cubes out of 5 attempted cubes in 40 minutes and 30 seconds, the judge should write down 3/5 40:30.
 - 9f4+) [CLARIFICATION] The result of an attempt should be a DNF if the competitor began the attempt by indicating that they are ready (see [Regulation A3b2](regulations:regulation:A3b2)) but the attempt was disqualified.
 - 9f5+) [CLARIFICATION] The result of an attempt is DNS if the competitor was eligible for the attempt and did not start it (see [Regulation A3b2](regulations:regulation:A3b2)). If the competitor did not qualify for an attempt (e.g. in a Cutoff Round), they have no result for the attempt.
 - 9p2+) [CLARIFICATION] Result refers to the single or average that determines the ranking of the corresponding round.