[gn] Fix typos in the documentation.

tools/gn/docs/quick_start.md

 # GN Quick Start guide
 
 [TOC]
 
 ## Running GN
 
 You just run `gn` from the command line. There is a script in
 depot\_tools (which is presumably on your path) with this name. The
 script will find the binary in the source tree containing the current
 directory and run it.
@@ skipping 248 matching lines @@
   sources = [
     "hello.cc",
   ]
   all_dependent_configs = [
     ":hello_config"
   ]
 }
 ```
 
 This applies the `hello_config` to the `hello` target itself, plus all
-targets that depend on transitively depend on the current one. Now
-everybody that depends on us will get our settings. You can also set
-`public_configs` which applies only to targets that directly
-depend on your target (not transitively).
+targets that transitively depend on the current one. Now everybody that
+depends on us will get our settings. You can also set `public_configs`
+which applies only to targets that directly depend on your target (not
+transitively).
 
 Now if you compile and run, you'll see the new version with two people:
 
 ```
 > ninja -C out/Default say_hello
 ninja: Entering directory 'out/Default'
 [1/1] Regenerating ninja files
 [4/4] LINK say_hello
 > out/Default/say_hello
 Hello, Bill and Joy.
@@ skipping 33 matching lines @@
 
 ```
 > gn desc out/Default //tools/gn/tutorial:say_hello defines --blame
 ...lots of other stuff omitted...
   From //tools/gn/tutorial:hello_config
        (Added by //tools/gn/tutorial/BUILD.gn:12)
     TWO_PEOPLE
 ```
 
 You can see that `TWO_PEOPLE` was defined by a config, and you can also
-see the which like caused that config to be applied to your target (in
+see the which line caused that config to be applied to your target (in

[brettw, 2016/01/19 23:59:46]

"see the which line"? Looks like we still have some work to do here :)

[Michael Achenbach, 2016/01/20 07:50:10]

Doh. The human brain is a weird thing. I probably concentrated too hard on
fixing one bug, so I missed the obvious other :)

 this case, the `all_dependent_configs` line).
 
 Another particularly interesting variation:
 
 ```
 gn desc out/Default //base:base_i18n deps --tree
 ```
 
 See `gn help desc` for more.
 
 ### Performance
 
 You can see what took a long time by running it with the --time command
 line flag. This will output a summary of timings for various things.
 
 You can also make a trace of how the build files were executed:
 
 ```
 gn --tracelog=mylog.trace
 ```
 
 and you can load the resulting file in Chrome's `about:tracing` page to
 look at everything.