CONTRIBUTING.md: Improve grammar

Fixes #1260

CONTRIBUTING.md

@@ -2,7 +2,7 @@
 
 Before reporting a bug, please take a look at the [FAQ](https://github.com/abo-abo/swiper/blob/master/README.md), as well as the [manual](http://oremacs.com/swiper/) and the [wiki](https://github.com/abo-abo/swiper/wiki). Please also make sure that there is not yet an existing issue.
 
-In order to fix it, we need to be able to reproduce the bug you encountered as closely as possible, so please describe the problem as detailed as you can. It is important that we can rule out interference with other emacs packages or customisations, therefore use `emacs -Q` to bypass your init file or use the shell code below to sandbox your emacs environment even further.
+In order to fix it, we need to be able to reproduce the bug you encountered as closely as possible, so please describe the problem in as much detail as possible. It is important that we can rule out interference with other Emacs packages or customisations, therefore use `emacs -Q` to bypass your init file. Running `make plain` will start Emacs and load the packages for you. If you want to sandbox your Emacs environment even further, use the shell code below.
 
 ```
 $ emacs --version
@@ -29,12 +29,12 @@ You can use `eval-expression` to load swiper/ivy and counsel and continue from t
 
 The basic code style guide is to use `(setq indent-tabs-mode nil)`. It is provided for you in [.dir-locals.el](https://github.com/abo-abo/swiper/blob/master/.dir-locals.el), please obey it.
 
-Before submitting the change, run `make compile` and `make test` to make sure that it doesn't introduce new compile warnings or test failures. Also run `make checkdoc` to see that your changes obey the documentation guidelines.
+Before submitting a change, run `make compile` and `make test` to make sure that it doesn't introduce new compilation warnings or cause tests to fail. Also run `make checkdoc` to see that your changes obey documentation guidelines.
 
 Use your own judgment for the commit messages, I recommend a verbose style using `magit-commit-add-log`.
 
 # Copyright Assignment
 
-These package are subject to the same [copyright assignment](http://www.gnu.org/prep/maintain/html_node/Copyright-Papers.html) policy as Emacs itself, org-mode, CEDET and other packages in [GNU ELPA](http://elpa.gnu.org/packages/). Any [legally significant](http://www.gnu.org/prep/maintain/html_node/Legally-Significant.html#Legally-Significant) contributions can only be accepted after the author has completed their paperwork. Please see [the request form](http://git.savannah.gnu.org/cgit/gnulib.git/tree/doc/Copyright/request-assign.future) if you want to proceed.
+These packages are subject to the same [copyright assignment](http://www.gnu.org/prep/maintain/html_node/Copyright-Papers.html) policy as Emacs itself, org-mode, CEDET and other packages in [GNU ELPA](http://elpa.gnu.org/packages/). Any [legally significant](http://www.gnu.org/prep/maintain/html_node/Legally-Significant.html#Legally-Significant) contributions can only be accepted after the author has completed their paperwork. Please see [the request form](http://git.savannah.gnu.org/cgit/gnulib.git/tree/doc/Copyright/request-assign.future) if you want to proceed with the assignment.
 
 The copyright assignment isn't a big deal, it just says that the copyright for your submitted changes to Emacs belongs to the FSF. This assignment works for all projects related to Emacs. To obtain it, you need to send one email, then send one letter (if you live in the US, it's digital), and wait for some time (in my case, I had to wait for one month).