lalpulsar_MakeSFTDAG.py: improve documentation of --window-type argument

Description

Clarify that --window-type tukey requires a parameter, and that if --window-type is unspecified lalpulsar_MakeSFTs defaults (i.e. tukey:0.001) are used.

Closes #668 (closed).

API Changes and Justification

Backwards Compatible Changes

• This change does not modify any class/function/struct/type definitions in a public C header file or any Python class/function definitions
• This change adds new classes/functions/structs/types to a public C header file or Python module

Backwards Incompatible Changes

• This change modifies an existing class/function/struct/type definition in a public C header file or Python module
• This change removes an existing class/function/struct/type from a public C header file or Python module

If any of the Backwards Incompatible check boxes are ticked please provide a justification why this change is necessary and why it needs to be done in a backwards incompatible way.

Review Status

@evan-goetz @david-keitel to approve.

requested review from @evan-goetz and @david-keitel

assigned to @karl-wette

added apinone lalpulsar labels

approved this merge request

Sorry @karl-wette I completely missed that.

Thanks @david-keitel - and no worries, it's not an urgent fix.

merged

mentioned in commit 694f0b75