Add Zack to team, update main authors to include team

Author: ZackPierce

CONTRIBUTING.md

@@ -141,9 +141,9 @@ Where we need help:
 
 ## Team
 
-| [<img alt="fitzgen" src="https://avatars2.githubusercontent.com/u/74571?s=117&v=4" width="117">](https://github.com/fitzgen) | [<img alt="pepyakin" src="https://avatars0.githubusercontent.com/u/2205845?s=117&v=4" width="117">](https://github.com/pepyakin) | [<img alt="DrGoldfire" src="https://avatars3.githubusercontent.com/u/1772277?s=117&v=4" width="117">](https://github.com/DrGoldfire) |
-|:---:|:---:|:---:|
-| [`fitzgen`](https://github.com/fitzgen) | [`pepyakin`](https://github.com/pepyakin) | [`DrGoldfire`](https://github.com/DrGoldfire) |
+| [<img alt="fitzgen" src="https://avatars2.githubusercontent.com/u/74571?s=117&v=4" width="117">](https://github.com/fitzgen) | [<img alt="pepyakin" src="https://avatars0.githubusercontent.com/u/2205845?s=117&v=4" width="117">](https://github.com/pepyakin) | [<img alt="DrGoldfire" src="https://avatars3.githubusercontent.com/u/1772277?s=117&v=4" width="117">](https://github.com/DrGoldfire) | [<img alt="ZackPierce" src="https://avatars0.githubusercontent.com/u/387703?s=400&v=4" width="117">](https://github.com/ZackPierce) |
+|:---:|:---:|:---:|:---:|
+| [`fitzgen`](https://github.com/fitzgen) | [`pepyakin`](https://github.com/pepyakin) | [`DrGoldfire`](https://github.com/DrGoldfire) | [`ZackPierce`](https://github.com/ZackPierce)
 
 Larger, more nuanced decisions about design, architecture, breaking changes,
 trade offs, etc are made by team consensus. In other words, decisions on things

wee_alloc/Cargo.toml

@@ -1,5 +1,10 @@
 [package]
-authors = ["Nick Fitzgerald <fitzgen@gmail.com>"]
+authors = [
+  "Nick Fitzgerald <fitzgen@gmail.com>",
+  "Sergey Pepyakin <s.pepyakin@gmail.com>",
+  "Matt Howell <mjhowell@gmail.com>",
+  "Zack Pierce <zachary.pierce@gmail.com>",
+]
 categories = ["memory-management", "web-programming", "no-std", "wasm", "embedded"]
 description = "wee_alloc: The Wasm-Enabled, Elfin Allocator"
 license = "MPL-2.0"