Move build configuration to peanut.yaml, make it easier to deploy example (dart-lang/markdown#379)

pkgs/markdown/build.yaml

diff --git a/pkgs/markdown/build.yaml b/pkgs/markdown/build.yaml
deleted file mode 100644
index 54b1fde..0000000
--- a/pkgs/markdown/build.yaml
+++ /dev/null
@@ -1,22 +0,0 @@
-# See https://github.com/dart-lang/build/tree/master/build_web_compilers#configuration
-targets:
-  $default:
-    builders:
-      build_web_compilers|dart2js_archive_extractor:
-        options:
-          # Ensures --dump-info .dart.js.info.json file is preserved.
-          # Useful to track compiled size change
-          filter_outputs: false
-      build_web_compilers|entrypoint:
-        # These are globs for the entrypoints you want to compile.
-        generate_for:
-        - example/**.dart
-        options:
-          dart2js_args:
-            - --dump-info
-            - --minify
-            - --no-frequency-based-minification
-            - --no-source-maps
-            - --show-package-warnings
-            - --trust-primitives
-            - --trust-type-annotations

pkgs/markdown/peanut.yaml

diff --git a/pkgs/markdown/peanut.yaml b/pkgs/markdown/peanut.yaml
new file mode 100644
index 0000000..7f20052
--- /dev/null
+++ b/pkgs/markdown/peanut.yaml
@@ -0,0 +1,16 @@
+# Configuration for https://pub.dev/packages/peanut
+directories:
+- example
+
+builder-options:
+  build_web_compilers|dart2js_archive_extractor:
+    # Ensures --dump-info .dart.js.info.json file is preserved.
+    # Useful to track compiled size change
+    filter_outputs: false
+  build_web_compilers|entrypoint:
+    dart2js_args:
+    - --dump-info
+    - --minify
+    - --no-frequency-based-minification
+    - --no-source-maps
+    - -O4