Fix repository organization, house cleaning

Added up-to-date install instructions and a simple image to the README.
Added an assets directory to house these things and some notes. Removed
`.gitlab-ci.yml` from being linked to the home directory, it does not
belong there.

home/.gitlab-ci.yml

@@ -1,36 +0,0 @@
----
-# This file is a template, and might need editing before it works on your project.
-# see https://docs.gitlab.com/ce/ci/yaml/README.html for all available options
-
-# you can delete this line if you're not using Docker
-image: fnichol/check-shell:latest
-
-analyze:
-  stage: test
-  before_script:
-    - shellcheck --version
-  script:
-    - echo "--------- CHECKING POSIX SHELLSCRIPTS -------------"
-    - find . -type f -name '*.sh' | xargs shellcheck -Calways
-    - echo "--------- CHECKING ZSH SHELLSCRIPTS -------------"
-    - find . -type f -name '*.zsh' | xargs shellcheck -Calways -s bash -e SC2034
-
-lint:
-  stage: test
-  before_script:
-    - shfmt -version
-  script:
-    - echo "--------- CHECKING POSIX SHELLSCRIPTS -------------"
-    - find . -type f -name '*.sh' | xargs shfmt -d -i 2
-    - echo "--------- CHECKING ZSH SHELLSCRIPTS -------------"
-    - find . -type f -name '*.zsh' | xargs shfmt -d -i 2
-
-test:
-  stage: test
-  image: alpine
-  before_script:
-    - apk add git bash
-    - git clone https://github.com/bats-core/bats-core.git /bats
-    - /bats/bin/bats --version
-  script:
-    - /bats/bin/bats -r .