Minor improvements for README.md.

Author: ascherer

README.md

@@ -11,24 +11,24 @@ they can be freely copied and modified to meet your organization's needs.
 
 The guidelines themselves are found at [CppCoreGuidelines](CppCoreGuidelines.md). There is also [a version formatted for browsing] (http://isocpp.github.io/CppCoreGuidelines/CppCoreGuidelines) that is manually integrated and thus slightly older than the version in the master branch.
 
-Many of the guidelines make use of the header only Guideline Support Library. One implementation is available at [GSL: Guideline Support Library](https://github.com/Microsoft/GSL).
+Many of the guidelines make use of the header-only Guideline Support Library. One implementation is available at [GSL: Guideline Support Library](https://github.com/Microsoft/GSL).
 
 ## Background and scope
 
 The aim of the guidelines is to help people to use modern C++ effectively. By "modern C++" we mean C++11 and C++14 (and soon C++17). In other
 words, what would you like your code to look like in 5 years' time, given that you can start now? In 10 years' time?
 
 The guidelines are focused on relatively higher-level issues, such as interfaces, resource management, memory management, and concurrency. Such
-rules affect application architecture and library design. Following the rules will lead to code that is statically type safe, has no resource
-leaks, and catches many more programming logic errors than is common in code today. And it will run fast - you can afford to do things right.
+rules affect application architecture and library design. Following the rules will lead to code that is statically type-safe, has no resource
+leaks, and catches many more programming logic errors than is common in code today. And it will run fast -- you can afford to do things right.
 
 We are less concerned with low-level issues, such as naming conventions and indentation style. However, no topic that can help a programmer is
 out of bounds.
 
-Our initial set of rules emphasize safety (of various forms) and simplicity. They may very well be too strict. We expect to have to introduce
+Our initial set of rules emphasizes safety (of various forms) and simplicity. They may very well be too strict. We expect to have to introduce
 more exceptions to better accommodate real-world needs. We also need more rules.
 
-You will find some of the rules contrary to your expectations or even contrary to your experience. If we haven't suggested you change your
+You will find some of the rules contrary to your expectations or even contrary to your experience. If we haven't suggested that you change your
 coding style in any way, we have failed! Please try to verify or disprove rules! In particular, we'd really like to have some of our rules
 backed up with measurements or better examples.