"Git Basics" chapter: tweak a couple things for aesthetics/clarity

 - use proper "em" dash
 - adjust wording to explain clone target directory name

Signed-off-by: Robert P. J. Day <[email protected]>

Author: rpjday

book/02-git-basics/sections/getting-a-repository.asc

@@ -73,7 +73,7 @@ $ git clone https://github.com/libgit2/libgit2
 That creates a directory named `libgit2`, initializes a `.git` directory inside it, pulls down all the data for that repository, and checks out a working copy of the latest version.
 If you go into the new `libgit2` directory that was just created, you'll see the project files in there, ready to be worked on or used.
 
-If you want to clone the repository into a directory named something other than `libgit2`, you can specify that as the next command-line option:
+If you want to clone the repository into a directory named something other than `libgit2`, you can specify the new directory name as an additional argument:
 
 [source,console]
 ----

ch02-git-basics-chapter.asc

@@ -22,5 +22,5 @@ include::book/02-git-basics/sections/aliases.asc[]
 
 === Summary
 
-At this point, you can do all the basic local Git operations – creating or cloning a repository, making changes, staging and committing those changes, and viewing the history of all the changes the repository has been through.
+At this point, you can do all the basic local Git operations -- creating or cloning a repository, making changes, staging and committing those changes, and viewing the history of all the changes the repository has been through.
 Next, we'll cover Git's killer feature: its branching model.