Fix validation errors according to validator.w3.org

* Add html lang tag
* Error: A charset attribute on a meta element found after the first 1024 bytes.
* Error: An img element must have an alt attribute, except under certain conditions.
* Error: Stray end tag input.
* Warning: The language attribute on the script element is obsolete. You can safely omit it.
* Error: An img element must have an alt attribute, except under certain conditions.
* Error: duplicate menu ids
* Baseof: Remove duplicate ids
* Warning: The border attribute is obsolete. Consider specifying img { border: 0; } in CSS instead.
* The border attribute is obsolete. Consider specifying img { border: 0; } in CSS instead.
* Error: Element f12 not allowed as child of element p in this context.
* Error: An img element must have an alt attribute, except under certain conditions.
* Stray end tag input.
* The language attribute on the script element is obsolete. You can safely omit it.
* Unclosed element div.