Completing missing important information about Generated Factories/Accessors

[mildabre]

I propose these 3 changes:

• add some important information about "generovane tovarny"
• remove misleading subheadings in "vicenasobne tovarny" Definice seznamem" and "Definice pomocí tagů" - because configuration definitions are important part of chapter "vicenasobne tovarny" - the subheading "Definice seznamem" creates an impression, that the chapter "Vicenasobne tovarny" is at the end !!
• remove non important information about alternative syntax
• point out that definition in configuration is required for correct function - because simple factory doesnt need such definition
• replace misleading code sample of definition by tags with a correct one

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