Add a short README that covers the monorepo

The language is roughly taken from the client README.

README.md

@@ -0,0 +1,23 @@
+> [There are many ways to contribute, and we welcome your help!](CONTRIBUTING.md) By contributing to this project, you agree to abide by our [Code of Conduct](https://github.com/freedomofpress/.github/blob/main/CODE_OF_CONDUCT.md).
+
+[![CircleCI](https://circleci.com/gh/freedomofpress/securedrop-client.svg?style=svg)](https://circleci.com/gh/freedomofpress/securedrop-client)
+[![Gitter](https://badges.gitter.im/Join%20Chat.svg)](https://gitter.im/freedomofpress/securedrop)
+
+# securedrop-client
+
+The SecureDrop Client is a desktop application for journalists to communicate with sources and work with submissions on the
+[SecureDrop Workstation](https://github.com/freedomofpress/securedrop-workstation). It runs within a [Qubes OS](https://www.qubes-os.org/intro/)
+virtual machine that has no direct network access and opens files within individual, non-networked, disposable VMs.
+
+This repository contains multiple components, including:
+* `client`: desktop GUI application
+* `export`: logic for exporting submissions
+* `log`: centralized logging
+* `proxy`: restricted HTTP proxy
+
+Each component's folder has a README with more detail.
+
+To learn more about architecture and our rationale behind our Qubes OS approach, see the
+[SecureDrop Workstation readme](https://github.com/freedomofpress/securedrop-workstation/blob/main/README.md).
+
+**IMPORTANT:** This project is currently undergoing a pilot study and should not be used in production environments.

client/README.md

@@ -1,8 +1,3 @@
-> [There are many ways to contribute, and we welcome your help!](CONTRIBUTING.md) By contributing to this project, you agree to abide by our [Code of Conduct](https://github.com/freedomofpress/.github/blob/main/CODE_OF_CONDUCT.md).
-
-[![CircleCI](https://circleci.com/gh/freedomofpress/securedrop-client.svg?style=svg)](https://circleci.com/gh/freedomofpress/securedrop-client)
-[![Gitter](https://badges.gitter.im/Join%20Chat.svg)](https://gitter.im/freedomofpress/securedrop?utm_source=badge&utm_medium=badge&utm_campaign=pr-badge)
-
 # securedrop-client
 
 The SecureDrop Client is a desktop application for journalists to communicate with sources and work with submissions on the [SecureDrop Workstation](https://github.com/freedomofpress/securedrop-workstation).

export/README.md

@@ -1,7 +1,3 @@
-> By contributing to this project, you agree to abide by our [Code of Conduct](https://github.com/freedomofpress/.github/blob/main/CODE_OF_CONDUCT.md).
-
-[![CircleCI](https://circleci.com/gh/freedomofpress/securedrop-export.svg?style=svg)](https://circleci.com/gh/freedomofpress/securedrop-export)
-
 # securedrop-export
 
 Code for exporting and printing files from the SecureDrop Qubes Workstation.

log/README.md

@@ -1,5 +1,3 @@
-> By contributing to this project, you agree to abide by our [Code of Conduct](https://github.com/freedomofpress/.github/blob/main/CODE_OF_CONDUCT.md).
-
 # securedrop-log
 
 `securedrop-log` is part of the [SecureDrop

proxy/README.md

@@ -1,9 +1,4 @@
-> By contributing to this project, you agree to abide by our [Code of Conduct](https://github.com/freedomofpress/.github/blob/main/CODE_OF_CONDUCT.md).
-
 ## securedrop workstation proxy
-
-[![CircleCI](https://circleci.com/gh/freedomofpress/securedrop-proxy.svg?style=svg)](https://circleci.com/gh/freedomofpress/securedrop-proxy)
-
 `securedrop-proxy` is part of the [SecureDrop
 Workstation](https://github.com/freedomofpress/securedrop-workstation) project.