Remove two proposals from the agenda

- Pipeline operator: There are some significant, recently filed issues with the proposal that need to be resolved before Stage 2 including tc39/proposal-pipeline-operator#82 and tc39/proposal-pipeline-operator#83 (as well as the arrow function grammar). I plan to follow up on these offline.
- Extensible literals: Changes to the proposal to incorporate feedback from the last presentation are still needed, but it's too close to the meeting to let others review these changes.

2018/01.md

@@ -120,9 +120,7 @@ Supporting materials includes slides, a link to the proposal repository, a link
     1. 60-minute items
         1. [`BigInt`](https://github.com/tc39/proposal-bigint) status update ([significant recent change](https://github.com/tc39/proposal-bigint/pull/106)) (Daniel Ehrenberg) ([slides](https://docs.google.com/presentation/d/1gXw9ewq8VzsWUuFgEHi-V2vx4tfZl5lJlkGQWw4iesE/edit#slide=id.p))
         1. [Static class features proposal](http://github.com/tc39/proposal-static-class-features/) (Daniel Ehrenberg)
-        1. [Pipeline operator](https://github.com/tc39/proposal-pipeline-operator) for Stage 2 (Daniel Ehrenberg) ([slides](https://docs.google.com/presentation/d/1EO8p3gAZQLa52r4987C0KD4vgm7O8M7pZQQq-sRmJ5g/edit#slide=id.p))
         1. [Decorators](https://github.com/tc39/proposal-decorators/) discussion towards Stage 3 (Daniel Ehrenberg) ([slides](https://docs.google.com/presentation/d/1g6hrJp_nk_OeapuPXlkE4D_31OZbz4wQbXuIagsyoUI/edit#slide=id.p))
-        1. [Extensible numeric literals](https://github.com/littledan/proposal-extensible-numeric-literals) update (Daniel Ehrenberg)
         1. Operator Overloading for Stage 1 (Keith Cirkel)
         1. Multi-module files for Stage 1 (Keith Cirkel)
 1. Non-timeboxed overflow from previous meeting