speedreader: Add license headers

Document each file as MPL 2.0-licensed, per code policy.
Addresses an `npm run presubmit` warning.

components/speedreader/rust/lib/src/readability/src/lib.rs

@@ -1,3 +1,8 @@
+// Copyright (c) 2021 The Brave Authors. All rights reserved.
+// This Source Code Form is subject to the terms of the Mozilla Public
+// License, v. 2.0. If a copy of the MPL was not distributed with this file,
+// You can obtain one at https://mozilla.org/MPL/2.0/.
+
 #[macro_use]
 extern crate html5ever;
 extern crate kuchikiki;

components/speedreader/rust/lib/src/readability/src/nlp.rs

@@ -1,3 +1,8 @@
+// Copyright (c) 2021 The Brave Authors. All rights reserved.
+// This Source Code Form is subject to the terms of the Mozilla Public
+// License, v. 2.0. If a copy of the MPL was not distributed with this file,
+// You can obtain one at https://mozilla.org/MPL/2.0/.
+
 use regex::{Regex, RegexSet};
 use std::cmp::max;
 use std::collections::HashSet;

components/speedreader/rust/lib/src/readability/src/scorer.rs

@@ -1,3 +1,8 @@
+// Copyright (c) 2021 The Brave Authors. All rights reserved.
+// This Source Code Form is subject to the terms of the Mozilla Public
+// License, v. 2.0. If a copy of the MPL was not distributed with this file,
+// You can obtain one at https://mozilla.org/MPL/2.0/.
+
 use crate::{dom, util};
 use html5ever::tendril::StrTendril;
 use html5ever::tree_builder::TreeSink;

components/speedreader/rust/lib/src/readability/src/statistics.rs

@@ -1,3 +1,8 @@
+// Copyright (c) 2021 The Brave Authors. All rights reserved.
+// This Source Code Form is subject to the terms of the Mozilla Public
+// License, v. 2.0. If a copy of the MPL was not distributed with this file,
+// You can obtain one at https://mozilla.org/MPL/2.0/.
+
 use crate::{dom, util};
 use kuchikiki::iter::NodeIterator;
 use kuchikiki::NodeRef as Handle;

components/speedreader/rust/lib/src/speedreader_readability.rs

@@ -1,3 +1,8 @@
+// Copyright (c) 2021 The Brave Authors. All rights reserved.
+// This Source Code Form is subject to the terms of the Mozilla Public
+// License, v. 2.0. If a copy of the MPL was not distributed with this file,
+// You can obtain one at https://mozilla.org/MPL/2.0/.
+
 use html5ever::driver::{ParseOpts, Parser};
 use html5ever::tendril::{StrTendril, TendrilSink};
 use kuchikiki::Sink;

components/speedreader/rust/lib/tests/legacy.rs

@@ -1,3 +1,8 @@
+// Copyright (c) 2021 The Brave Authors. All rights reserved.
+// This Source Code Form is subject to the terms of the Mozilla Public
+// License, v. 2.0. If a copy of the MPL was not distributed with this file,
+// You can obtain one at https://mozilla.org/MPL/2.0/.
+
 #![allow(dead_code)]
 extern crate distance;
 extern crate html5ever;

components/speedreader/rust/lib/tests/lib.rs

@@ -1,3 +1,8 @@
+// Copyright (c) 2021 The Brave Authors. All rights reserved.
+// This Source Code Form is subject to the terms of the Mozilla Public
+// License, v. 2.0. If a copy of the MPL was not distributed with this file,
+// You can obtain one at https://mozilla.org/MPL/2.0/.
+
 #![allow(dead_code)]
 extern crate distance;
 extern crate html5ever;