fix signature doc vko() to vkw()

[Xeite]

Pull Request Check List

Please make sure that you tick all appropriate boxes.

• Added tests for changed code.
• Updated documentation for changed code.
• Documentation in .rst files is written using semantic newlines.
• Changed/added classes/methods/functions have appropriate versionadded, versionchanged, or deprecated directives.

If you have any questions to any of the points above, just submit and ask! This checklist is here to help you, not to deter you from contributing!

[coveralls]

Pull Request Test Coverage Report for Build 74

• 0 of 0 changed or added relevant lines in 0 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage remained the same at ?%

---

Totals
Change from base Build 72:	0.0%
Covered Lines:
Relevant Lines:	0

---

💛 - Coveralls

[coveralls]

Pull Request Test Coverage Report for Build 74

• 0 of 0 changed or added relevant lines in 0 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage remained the same at ?%

---

Totals
Change from base Build 72:	0.0%
Covered Lines:
Relevant Lines:	0

---

💛 - Coveralls