Is skills or abilities of the worker taking in consideration in Marx law of value?
Labour power is a commodity like any other. Its value is consequently a function of the labour embodied in it.

Taking your example,


product A (a webpage)
takes 10 hours
you need special skills (those of a webdesigner) that are hard to learn
only 14% of population already have those skills to build that
product


Versus


product B (a chair)
takes 10 hours
you do not need special skills (you do; those of carpenter. But those are easier to learn, compared to those of a webdesigner)
90% of the people (probably an exageration, but certainly more people have the skills of a carpenter than those of a webdesigner) already have those skills to build that product 


A value = B value ?
the chair value = the web site value?

No.

While each of them requires 10 hours of labour, the labour embodied in each has a different value.

The labour of the webdesigner is more valuable.

Why?

Because it takes - say - 1,000 hours of labour to turn an unskilled labourer into a webdesigner, while it takes - say - 200 hours of labour to turn an unskilled labourer into a carpenter.