[devdocsgjs/main: 1058/1867] Document thor docs:download --all

[Andy Holmes <andyholmes src gnome org>]

commit fd5b25c92adb80c2b39431f8fc9d993d99886b8d
Author: Rick Mac Gillis <8941225+rickmacgillis users noreply github com>
Date:   Mon May 18 09:07:50 2020 -0400

    Document thor docs:download --all

 README.md | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/README.md b/README.md
index 63d31ddc..cecd5627 100644
--- a/README.md
+++ b/README.md
@@ -30,7 +30,7 @@ bundle exec rackup
 
 Finally, point your browser at [localhost:9292](http://localhost:9292) (the first request will take a few 
seconds to compile the assets). You're all set.
 
-The `thor docs:download` command is used to download pre-generated documentations from DevDocs's servers 
(e.g. `thor docs:download html css`). You can see the list of available documentations and versions by 
running `thor docs:list`. To update all downloaded documentations, run `thor docs:download --installed`.
+The `thor docs:download` command is used to download pre-generated documentations from DevDocs's servers 
(e.g. `thor docs:download html css`). You can see the list of available documentations and versions by 
running `thor docs:list`. To update all downloaded documentations, run `thor docs:download --installed`. To 
download and install all documentation this project has available, run `thor docs:download --all`.
 
 **Note:** there is currently no update mechanism other than `git pull origin master` to update the code and 
`thor docs:download --installed` to download the latest version of the docs. To stay informed about new 
releases, be sure to [watch](https://github.com/freeCodeCamp/devdocs/subscription) this repository.