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Readme.md

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+<!--
+ Copyright 2022 Jeremy Wall (Jeremy@marzhilsltudios.com)
+ 
+ Licensed under the Apache License, Version 2.0 (the "License");
+ you may not use this file except in compliance with the License.
+ You may obtain a copy of the License at
+ 
+     http://www.apache.org/licenses/LICENSE-2.0
+ 
+ Unless required by applicable law or agreed to in writing, software
+ distributed under the License is distributed on an "AS IS" BASIS,
+ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ See the License for the specific language governing permissions and
+ limitations under the License.
+-->
+
+# tracing-browser-subscriber
+
+This implements a minimal [tracing](https://crates.io/crates/tracing) subscriber for use in browser/webassembly.
+It allows you to use tracing in the browser to log as well as record timings for spans. At the time of writing it 
+differs from [tracing-wasm](https://crates.io/crates/tracing) in the following ways.
+
+* It does not support colors in the log output.
+* It does not mark or measure events in the browser performance data only spans.
+* It use the console `error`, `warn`, `info`, `debug`, and `trace` mechanism to record logs.
+
+If the above features/restrictions do not appeal to you you may want to use `tracing-wasm` instead.
+
+## Example
+
+```rust
+use tracing_browser_subscriber;
+use wasm_bindgen::prelude::wasm_bindgen;
+
+#[wasm_bindgen(start)]
+fn main() {
+    tracing_browser_subscriber::configure_as_global_default();
+    // Rest of our webassembly code goes here
+}
+```