[fpc-pascal] Searchable docs online

[Michael Van Canneyt]

Hello,

Given the questions of late, I have created a search page for the docs:

https://www.freepascal.org/docsearch/docsearch.html

This will search in the manuals, and in the reference documentation for the
units.

There is ample room for improvement, but the page already works.

Things to improve:
- Allow 'contains' 
- Allow 'minimum rank' (rank is the number of times a word appears in a page)
- Allow to specify in which manual you want to search.
- Integrate searching in the doc pages themselves.

The underlying mechanisms for this search are 100% FPC based: 
fpindexer, fcl-web, and the webpage logic is done using pas2js.
(meaning you need to have Javascript enabled)

Feedback and comments welcome.

Michael.