Missing "true" string from a couple of JP sentences

[valadzhov]

Steps to reproduce:

1. Check out the 8.2.x documentation.
2. Open Notepad++ and search in the EN typedoc folder for "Returns if".
3. Examine the results.

Actual Results:
There are a couple of strings which don't specify what is expected to be returned (it's actually "true" which has to be returned). The "true" is also missing from the EN source but I think it would be nice if we have it in the JP documentation:

Returns if the IgxGridComponent has sortable columns.
Returns if the filtering is enabled.
Returns if the IgxGridComponent has fiterable columns.

Expected results:
Returns true if the IgxGridComponent has sortable columns.
Returns true if the filtering is enabled.
Returns true if the IgxGridComponent has fiterable columns.

This has to be fixed in all versions and it's with very low priority.