README and ISSUE_TEMPLATE: quote $(brew --repo)

Always a good idea to quote command substitution.

.github/ISSUE_TEMPLATE.md

-If Homebrew was updated on Aug 10-11th 2016 and `brew update` always says `Already up-to-date.` you need to run: `cd $(brew --repo) && git fetch && git reset --hard origin/master && brew update`.
+If Homebrew was updated on Aug 10-11th 2016 and `brew update` always says `Already up-to-date.` you need to run: `cd "$(brew --repo)" && git fetch && git reset --hard origin/master && brew update`.
 
 # Please follow the general troubleshooting steps first:
 

README.md

@@ -4,7 +4,7 @@ Features, usage and installation instructions are [summarised on the homepage](h
 ## Update Bug
 If Homebrew was updated on Aug 10-11th 2016 and `brew update` always says `Already up-to-date.` you need to run:
 ```bash
-cd $(brew --repo) && git fetch && git reset --hard origin/master && brew update
+cd "$(brew --repo)" && git fetch && git reset --hard origin/master && brew update
 ```
 
 ## What Packages Are Available?