HTML validation adjustments to about.pl

HTML validation adjustments to about.pl

Corrects the Tidy errors:
line 428 column 19 - Error: "tr" not finished but containing element ended
line 428 column 19 - Error: end tag for "tr" omitted, but OMITTAG NO was specified
line 426 column 25 - Info: start tag was here
line 452 column 31 - Error: end tag for "strong" omitted, but OMITTAG NO was specified
line 452 column 12 - Info: start tag was here
line 518 column 17 - Error: document type does not allow element "ul" here; missing one of "object", "applet", "map", "iframe", "button", "ins", "del" start-tag
line 525 column 17 - Error: document type does not allow element "ul" here; missing one of "object", "applet", "map", "iframe", "button", "ins", "del" start-tag

Signed-off-by: Galen Charlton <galen.charlton@liblime.com>