build: set legacy-peer-deps for npm 7

We have some peerDependency mismatches in our install tree. In npm 6
this was OK (maybe reason for a warning) but in npm 7 they hard fail the
install.

.npmrc

@@ -0,0 +1 @@
+legacy-peer-deps=true

package.json

@@ -32,9 +32,9 @@
     "@uppy-example/php-xhr": "file:examples/php-xhr",
     "@uppy-example/python-xhr": "file:examples/python-xhr",
     "@uppy-example/react-example": "file:examples/react-example",
-    "@uppy-example/svelte-example": "file:examples/svelte-example",
     "@uppy-example/react-native-expo": "file:examples/react-native-expo",
     "@uppy-example/redux": "file:examples/redux",
+    "@uppy-example/svelte-example": "file:examples/svelte-example",
     "@uppy-example/transloadit": "file:examples/transloadit",
     "@uppy-example/transloadit-textarea": "file:examples/transloadit-textarea",
     "@uppy-example/uppy-with-companion": "file:examples/uppy-with-companion",