Add the logo and few minor updates

Add the logo and incorporating minor suggestions from Scott.

README.md

@@ -1,23 +1,21 @@
-# Welcome to Mojo
+# Welcome to Mojo 🔥
 
 Mojo is a new programming language that bridges the gap between research 
 and production by combining Python syntax and ecosystem with systems 
-programming and metaprogramming features. Mojo is still early, but it is designed
-to become a superset of 
-Python over time.  This will allow Python's dynamic features to continue
-to shine but also unleash Python from the shackles of C and C++ under the hood.
+programming and metaprogramming features. Mojo is still young, but it is designed
+to become a superset of Python over time.  
 
-We expect Mojo to be open-sourced progressively over time, but for now it's still 
-young and changing very quickly. We believe that a small,tight-knit group of 
+We plan to open-source Mojo progressively progressively over time, but for now it's 
+early and changing rapidly. We believe that a small, tight-knit group of 
 engineers with a shared vision can move faster than a community effort, so we will
 continue to incubate it within Modular until it's more complete.  Please see the 
 [Mojo FAQ](https://docs.modular.com/mojo/faq.html) for answers to this and other 
 common questions. 
 
 We've opened this repo now because we want to gather issues and engage in feedback 
 from users who have access to the Mojo Playground (our hosted JupyterHub
-where you can try coding with an early version of Mojo). To get access to the
-Mojo Playground, [see here to sign up](https://docs.modular.com/mojo/get-started.html).
+where you can try coding with an early version of Mojo). 
+To get access to the Mojo Playground, [see here to sign up](https://docs.modular.com/mojo/get-started.html).
 Then, when you want to report issues or request features,
 [please create a GitHub issue here](https://github.com/modularml/mojo/issues).