feat(cli): support import of .md files

Signed-off-by: Phil Kuang <pkuang@factset.com>

packages/cli/asset-types/asset-types.d.ts

@@ -40,6 +40,11 @@ declare module '*.jpeg' {
   export default src;
 }
 
+declare module '*.md' {
+  const src: string;
+  export default src;
+}
+
 declare module '*.png' {
   const src: string;
   export default src;

packages/cli/src/lib/builder/config.ts

@@ -132,6 +132,7 @@ export async function makeRollupConfigs(
               /\.woff$/,
               /\.woff2$/,
               /\.ttf$/,
+              /\.md$/,
             ],
           }),
           json(),