Update textual.html.erb.md

Just a wording suggestion.
Update complex.html.erb.md

See edits above. What about the idea of an html5 icon next to html5 techniques?
Update groups.html.erb.md

see one type change above. 1966 changed to 1936
Update multi-directional.html.erb.md

I found the first example here confusing because clearly there were cities in name columns and cities in first or last name columns. See other typo corrections above.
Update caption-summary.html.erb.md

In the example: "Using the <figure> element to mark up a table summary" I wasn't sure if I should or shouldn't use the aria techniques. See minor edits above.
Merge pull request #99 from hkramer/patch-5

Update textual.html.erb.md
Merge pull request #100 from hkramer/patch-6

Update complex.html.erb.md
Some additional wording

(complimentary to #100)

Signed-off-by: Eric Eggert <ee@w3.org>
Merge pull request #101 from hkramer/patch-7

Typo. Update groups.html.erb.md
Merge pull request #102 from hkramer/patch-8

Typos. Update multi-directional.html.erb.md
Merge pull request #103 from hkramer/patch-9

Update caption-summary.html.erb.md
Clarify alt decision tree
Merge branch 'master' of github.com:w3c/wai-tutorials

# By hkramer
# Via Eric Eggert (1) and hkramer (1)
* 'master' of github.com:w3c/wai-tutorials:
  Update caption-summary.html.erb.md
Wording, comma
Remove quotes from link
Remove external link images in exsamples
Wording
Wording
Consistent wording
Wording, Style