lint: fix `MD012/no-multiple-blanks` rule

Multiple consecutive blank lines [Expected: 2; Actual: 3]

books/free-programming-books-fa_IR.md

@@ -76,5 +76,3 @@
 * [تحلیل شبکه‌های اجتماعی در R](http://cran.r-project.org/doc/contrib/Raeesi-SNA_in_R_in_Farsi.pdf) (PDF)
 * [راهنمای زبان R](http://cran.r-project.org/doc/contrib/Mousavi-R-lang_in_Farsi.pdf) (PDF)
 * [موضعات ویژه در R](http://cran.r-project.org/doc/contrib/Mousavi-R_topics_in_Farsi.pdf) (PDF)
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casts/free-podcasts-screencasts-ru.md

@@ -137,5 +137,3 @@
 ### Webpack
 
 * [Скринкаст Webpack](https://learn.javascript.ru/screencast/webpack) - Илья Кантор (Screencast)
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courses/free-courses-kk.md

@@ -37,5 +37,3 @@ ADVANCED - дамытушы. Детальді кодты үйрену.
 ### Python
 
 * [Python тiлiнде бағдарламалау негiздерi.](https://openu.kz/kz/courses/python-tilinde-badarlamalau-negizderi) - Жасдәурен Дүйсебеков (Қазақстанның ашық университеті) *(тіркелуді талап етпейді)*
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more/free-programming-interactive-tutorials-ru.md

@@ -44,5 +44,3 @@
 ### SQL
 
 * [SQL упражнения](https://www.sql-ex.ru/?Lang=0)
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