File model and api is almost complete

- Added "Kind" field to File model
- Added file query
- Added editFile mutation
- Added removeFile mutation

schema/types/file.graphql

@@ -0,0 +1,43 @@
+# A File contains information about a file and where to download it.
+type File {
+  # The file's unique ID
+  id: String!
+
+  # The kind of file. Most will be "upload", but some that are ported from the wiki will have other values for this.
+  kind: String!
+
+  # The time of uploading
+  time: String!
+
+  # Whether the file is publicly listable. Someone with knowledge of the ID
+  # will still be able to view it, however.
+  public: Boolean!
+
+  # The file's name
+  name: String!
+
+  # The MIME type of the file
+  mimeType: String!
+
+  # The file's size in bytes
+  size: Int!
+
+  # The uploader
+  author: String!
+
+  # The URL where the file is hosted
+  url: String
+}
+
+# Input for editFile mutation
+input EditFileInput {
+ # The file's unique ID
+  id: String!
+
+  # Whether the file is publicly listable. Someone with knowledge of the ID
+  # will still be able to view it, however.
+  public: Boolean
+
+  # The file's name
+  name: String
+}