Update readme.md.

* fix typo
* use a code block for the local commands
Update .gitignore and _config.yml.

* ignore "*.json" files in "_config.yml"
* remove unneeded ignores from "_config.yml"
Update package.json.

Remove unneeded properties.
Merge pull request #129 from XhmikosR/gh-pages-various

Update Readme.md, _config.yml and clean up package.json