adding separators to README

**in this PR I did basically:**

- *add separators to README file*

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**I did this because:**

- *i feel it improves the overall flow of the file*

README.md

@@ -5,10 +5,14 @@
 
 **Docs:** [Docker](docs/docker.md), [Metrics](docs/metrics.md)
 
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 ## What it does
 
 A file sharing experiment which allows you to send encrypted files to other users.
 
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 ## Requirements
 
 - [Node.js 8+](https://nodejs.org/)
@@ -20,6 +24,8 @@ A file sharing experiment which allows you to send encrypted files to other user
 $ redis-server /usr/local/etc/redis.conf
 ```
 
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 ## How to use it
 
 | Command          | Description |
@@ -30,14 +36,20 @@ $ redis-server /usr/local/etc/redis.conf
 | `npm start`      | Starts the Express web server.
 | `npm test`       | Runs the suite of mocha tests.
 
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 ## Localization
 
 Firefox Send localization is managed via [Pontoon](https://pontoon.mozilla.org/projects/test-pilot-firefox-send/), not direct pull requests to the repository. If you want to fix a typo, add a new language, or simply know more about localization, please get in touch with the [existing localization team](https://pontoon.mozilla.org/teams/) for your language, or Mozilla’s [l10n-drivers](https://wiki.mozilla.org/L10n:Mozilla_Team#Mozilla_Corporation) for guidance.
 
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 ## Contributing
 
 Pull requests are always welcome! Feel free to check out the list of ["good first bugs"](https://github.com/mozilla/send/issues?q=is%3Aopen+is%3Aissue+label%3A%22good+first+bug%22).
 
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 ## Testing
 
 | ENVIRONMENT | URL
@@ -46,6 +58,10 @@ Pull requests are always welcome! Feel free to check out the list of ["good firs
 | Stage       | <https://send.stage.mozaws.net/>
 | Development | <https://send.dev.mozaws.net/>
 
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 ## License
 
 [Mozilla Public License Version 2.0](LICENSE)
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