Docs: document UI rules event and @runtime (#110)

* Docs: document UI rules event and @runtime

Signed-off-by: Sami Salonen <ssalonen@gmail.com>

* docs: additional disclaimer with String items

Signed-off-by: Sami Salonen <ssalonen@gmail.com>

* docs: TOC showing h2..h3 only

Signed-off-by: Sami Salonen <ssalonen@gmail.com>

* Docs: Capitalization of Java/JavaScript

Signed-off-by: Sami Salonen <ssalonen@gmail.com>

* docs: Wording correections. Mention "jsscripting" also

Signed-off-by: Sami Salonen <ssalonen@gmail.com>

* docs: cross-reference event object file/UI documentation sections

Signed-off-by: Sami Salonen <ssalonen@gmail.com>

* docs: Remove empty column

Signed-off-by: Sami Salonen <ssalonen@gmail.com>

* Docs: clarifying installation section

Signed-off-by: Sami Salonen <ssalonen@gmail.com>
Co-Authored-By: Dan Cunningham <dan@digitaldan.com>

Co-authored-by: Dan Cunningham <dan@digitaldan.com>

* docs: Advanced Scripting with @runtime

Signed-off-by: Sami Salonen <ssalonen@gmail.com>

* docs: Move scriptLoaded/scriptUnloaded hooks under File Based Rules

Also:
- title capitalization now reflecting code

Signed-off-by: Sami Salonen <ssalonen@gmail.com>

* Remove openhab timer

Emulating merge error with #99

Signed-off-by: Sami Salonen <ssalonen@gmail.com>

* Merge fixing

Emulating merge error with #99

Signed-off-by: Sami Salonen <ssalonen@gmail.com>

Signed-off-by: Sami Salonen <ssalonen@gmail.com>

Co-authored-by: Dan Cunningham <dan@digitaldan.com>