Allow CJK characters and Latin letters join without whitespace

[Saltsmart]

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Is your feature request related to a problem? Please describe.

I'm always frustrated when I write academic reports in my mother tongue and found many false positives (MORFOLOGIK_RULE_EN_US).
I have found these mistakes are caused by the join of CJK (Chinese, Japanese and Korean) characters and Latin letters without whitespace.

Describe the solution you'd like

Please allow CJK characters and Latin letters join without whitespace.

Describe alternatives you've considered

Disable language checking for the specific characters (For example, The basic block named CJK Unified Ideographs (4E00–9FFF) contains 20,992 basic Chinese characters in the range U+4E00 through U+9FFF.), or replace them with dummy contents.

Additional context

If you are familiar with Chinese, this website presents a nice discussion for the problem:
中西文混排时汉字与拉丁字母之间是否要有空格？