Support .pyi python files

[konstin]

Python uses .pyi files for type stubs, type annotations that live outside the main source code. While these files are not executed, they contain valid python and are written and read as such by humans and tools such as type checkers and IDEs.

On typeshed, the main repository for type stubs in python:

before

━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
 Language            Files        Lines         Code     Comments       Blanks
━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
 INI                     1            7            7            0            0
 JSON                    4          217          217            0            0
 Python                 77         7687         5514          624         1549
 Shell                   2          152           88           43           21
 Plain Text            160         4283            0         3870          413
 TOML                  157          897          708          112           77
───────────────────────────────────────────────────────────────────────────────
 Markdown                6         1177            0          925          252
 |- BASH                 3           28           27            1            0
 |- PowerShell           1            4            4            0            0
 |- Python               3           47           39            0            8
 (Total)                           1256           70          926          260
━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
 Total                 407        14499         6604         5575         2320
━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

after

━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
 Language            Files        Lines         Code     Comments       Blanks
━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
 INI                     1            7            7            0            0
 JSON                    4          217          217            0            0
 Python               4386       280564       252860         4131        23573
 Shell                   2          152           88           43           21
 Plain Text            160         4283            0         3870          413
 TOML                  157          897          708          112           77
───────────────────────────────────────────────────────────────────────────────
 Markdown                6         1177            0          925          252
 |- BASH                 3           28           27            1            0
 |- PowerShell           1            4            4            0            0
 |- Python               3           47           39            0            8
 (Total)                           1256           70          926          260
━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
 Total                4716       287376       253950         9082        24344
━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

[XAMPPRocky]

Thank you for your PR, and congrats on your first contribution! 🎉