ICU-20033 Add a top-level README.md (unicode-org#11)

* ICU-20033: add a README.md

- add a basic README.md linking to icu4c and icu4j

PR-URL: unicode-org#11

Author: srl295

README.md

@@ -0,0 +1,34 @@
+#  International Components for Unicode
+
+This is the repository for the [International Components for Unicode](http://site.icu-project.org). 
+The ICU project is under the stewardship of [The Unicode Consortium](https://www.unicode.org).
+
+- Source: https://github.com/unicode-org/icu
+- Bugs: https://unicode-org.atlassian.net/projects/ICU
+
+![ICU Logo](./tools/images/iculogo_64.png)
+
+### Build Status
+
+Build | Status
+------|-------
+TravisCI | [![Build Status](https://travis-ci.org/unicode-org/icu.svg?branch=master)](https://travis-ci.org/unicode-org/icu)
+Win x64 Release | [![Build status](https://unicode-icu.visualstudio.com/ICU/_apis/build/status/ICU4C%20Build%20and%20Test%20%5Bx64%20Release%5D%20(CI))](https://unicode-icu.visualstudio.com/ICU/_build/latest?definitionId=8)
+Win x86 Release | [![Build status](https://unicode-icu.visualstudio.com/ICU/_apis/build/status/ICU4C%20Build%20and%20Test%20%5Bx86%20Release%5D%20(CI))](https://unicode-icu.visualstudio.com/ICU/_build/latest?definitionId=7)
+
+
+### Subdirectories and Information
+
+- [`icu4c/`](./icu4c/) [ICU for C/C++](./icu4c/readme.html)
+- [`icu4j/`](./icu4j/) [ICU for Java](./icu4j/readme.html)
+- [`tools/`](./tools/) Tools
+- [`vendor/`](./vendor/) Vendor dependencies
+
+### License
+
+Please see [./icu4c/LICENSE](./icu4c/LICENSE) (C and J are under an identical license file.)
+
+> Copyright © 2016 and later Unicode, Inc. and others. All Rights Reserved.
+Unicode and the Unicode Logo are registered trademarks 
+of Unicode, Inc. in the U.S. and other countries.
+[Terms of Use and License](http://www.unicode.org/copyright.html)