Add mdbook team

We need to create a team to maintain mdBook.  The people listed here
have volunteered.  We'll put out a call for volunteers and adjust as
we hear more.

Author: traviscross

repos/rust-lang/mdBook.toml

@@ -11,16 +11,12 @@ path = "/"
 
 [access.teams]
 devtools = "write"
-
-[access.individuals]
-# Dylan-DPC is maintaining mdbook along with ehuss. Planning to add a team
-# soon, and then this can be removed.
-Dylan-DPC = "write"
+mdbook = "write"
 
 [[rulesets]]
 pattern = "master"
 ci-checks = ["Success gate"]
-required-approvals = 0
+required-approvals = 1
 merge-queue = { enabled = true, min-entries-to-merge-wait-minutes = 1 }
 
 [[crates-io]]

teams/mdbook.toml

@@ -0,0 +1,22 @@
+name = "mdbook"
+subteam-of = "devtools"
+
+[people]
+leads = ["ehuss"]
+members = [
+    "ehuss",
+    "traviscross",
+    "PLeVasseur",
+    "Mark-Simulacrum",
+    "eholk",
+]
+
+alumni = []
+
+[[github]]
+orgs = ["rust-lang"]
+
+[website]
+name = "mdBook team"
+description = "Maintaining mdBook"
+repo = "https://github.com/rust-lang/mdBook"