Update articles/css-colors-borders-backgrounds.html

Fixed some wording and grammar errors. Still want to add a little to the color section as time allows.
Merge pull request #8 from cidcoto/patch-1

Update articles/css-colors-borders-backgrounds.html
Minor changes
Merge pull request #9 from devihalim/patch-1

Minor changes
Update articles/html-structural-elements.html
Merge pull request #10 from ADLBlue/patch-1

Update articles/html-structural-elements.html