Update docs/index.rst

Added difference between app and feature explanation
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changed a sentence
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removed uneccessary sentence
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+ sentence
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Update docs/index.rst
Update tasks.py

added task select_features
Added jsbasics feature providing jquery and underscore.js
added django_productline to installed apps
added product name, container name and product dir to the product context
added media_includes; uses block private_css/js instead of admin_css/jss
added compressor to INSTALLED_APPS;
Changed dpl.settings.DEBUG to False; Added development feature refining DEBUG to True
Added ALLOWED_HOSTS=["*"] to dpl settings
Added compressor.finders.CompressorFinder as staticfiles feature combined with compressor requires
Staticfiles only adds staticfiles urlpatterns if DEBUG true;
moved import to inner function to avoid import guard issue
removed unused import
removed compressor static file finder from static file finders as compressor is now an own feature.
removed compressor from installed apps @dpl