Update the gclient config instructions to not use relative paths. As of https://codereview.chromium.org/1406053003 relative paths are no longer valid for the solution name. Update the docs to use the full current directory instead. BUG=angleproject:1204 Change-Id: I42b289fdad6d85901f431bb701f2a08e0ad0deb3 Reviewed-on: https://chromium-review.googlesource.com/311180 Reviewed-by: Jamie Madill <jmadill@chromium.org> Tested-by: Geoff Lang <geofflang@chromium.org>