Recommend to do not normalize unknown files by default

Also recommend to remove warnings for well know files normalization
Apply the recommendation for gitattributes file in this repo
Fix error on "dealing with line endings" link
Update index.md
Remove TODO comments
Remove weird characters
Add attribution
Updated Working-With-git site about git extensions issues.
Merge pull request #30 from andresmoschini/line-ending-doc-fixes

Recommend to do not normalize unknown files by default
Merge pull request #32 from andresmoschini/mmeliendrez-patch-1

Add content to "Why Migrate" section
Updated Git Extension issues section.
Merge pull request #35 from fmontenegro/MigrationToGitDraft

Updated Working-With-git site about git extensions issues.
Format some texts on "Git Extensions Issues"
Update git-extension-issues.md
Remove Matias' collection from external resources

Fixes #34
Add "Atlassian Sourcetree Pros" section into Git Client->Atlassian Sourcetree.
Merge pull request #36 from leoslopez/source-tree-review

Add "Atlassian Sourcetree Pros" section into Git Client->Atlassian Sourc...
Update git-extension-issues.md
Update git-extension-issues.md
Create _config.yml

Add _config.yml in order to help to get a better local building to test site generation.