Revert "Tag version 1.1.0"

This reverts commit 07f69dd.

We need to temporarily revert this while we tag a stable version
for SymbolKit and any other downstream dependencies in the DocC stack.

Author: bitjammer

CHANGELOG.md

@@ -18,7 +18,7 @@ let package = Package(
     // name, platforms, products, etc.
     dependencies: [
         // other dependencies
-        .package(url: "https://github.com/apple/swift-docc-plugin", from: "1.1.0"),
+        .package(url: "https://github.com/apple/swift-docc-plugin", from: "1.0.0"),
     ],
     targets: [
         // targets