Double period in references

[mattgarrish]

Description of problem

What happened (e.g., it crashed)?:

Very minor nit, but I noticed that generated references don't account for the last editor already having a period at the end of their name.

For example, you get two periods because of "Jr." in this reference:

CSS Cascading and Inheritance Level 5. Elika Etemad; Miriam Suzanne; Tab Atkins Jr.. W3C. 13 January 2022. W3C Candidate Recommendation. URL: https://www.w3.org/TR/css-cascade-5/

Expected behavior (e.g., it shouldn't crash):

If the last editor's name ends in a period, omit a second period.

[marcoscaceres]

Offending line is here:

respec/src/core/render-biblio.js

Line 235 in 0409aa0

output += ". ";