fix: Add syntax highlighting to code blocks

command-line-utils/generating-transition-between-images.md

@@ -1,6 +1,6 @@
-I have lots of images of a scene from sunrise to sunset and my wallpaper is automaticatilly set to one of them based on the hour of the day. But you know what? I LOVE customizing my machine and I WANT MORE! I want the transition to be smooth af. To make this possible I need to generate images. And here is the result of literally 5 minutes of google search:
+I have lots of images of a scene from sunrise to sunset and my wallpaper is automatically set to one of them based on the hour of the day. But you know what? I LOVE customizing my machine and I WANT MORE! I want the transition to be smooth af. To make this possible I need to generate images. And here is the result of literally 5 minutes of google search:
 
-```
+```bash
 convert A.jpg B.jpg -morph 10 out.jpg
 ```
 

command-line-utils/getting-the-keys-pressed.md

@@ -1,4 +1,4 @@
 Most of the time, `xev` will be enough to know exactly which key is pressed but it generates a lot of output and sometimes that is overwhelming. If you find yourself in this situation try: 
-```
+```bash
 showkey -a
 ```

command-line-utils/joining-images-into-one.md

@@ -1,7 +1,8 @@
 You can join multiple images into one using `convert`:
-  
-    # join vertically
-    convert in1.png in2.png -append out.png
+```bash
+# join vertically
+convert in1.png in2.png -append out.png
 
-    # join horizontally 
-    convert in1.png in2.png +append out.png
+# join horizontally 
+convert in1.png in2.png +append out.png
+```

command-line-utils/joining-images-to-pdf.md

@@ -1,22 +1,26 @@
 You can join multiple images to pdf using `convert`:
 
-    convert *.png out.pdf
+```bash
+convert *.png out.pdf
+```
 
 If you get an error like 
-
-    convert-im6.q16: attempt to perform an operation not allowed by the security policy `PDF' @ error/constitute.c/IsCoderAuthorized/408.
+```
+convert-im6.q16: attempt to perform an operation not allowed by the security policy `PDF' @ error/constitute.c/IsCoderAuthorized/408.
+```
 
 follow the steps below:
-
-    sudo vim /etc/ImageMagick-6/policy.xml
+```bash
+sudo vim /etc/ImageMagick-6/policy.xml
+```
 
 and replace the line 
-
-    <policy domain="coder" rights="none" pattern="PDF" />
-
+```xml
+<policy domain="coder" rights="none" pattern="PDF" />
+```
 with
-
-    <policy domain="coder" rights="read|write" pattern="PDF" />
-
+```xml
+<policy domain="coder" rights="read|write" pattern="PDF" />
+```
 
 [source](https://askubuntu.com/questions/1081895/trouble-with-batch-conversion-of-png-to-pdf-using-convert)

command-line-utils/joining-pdf-files.md

@@ -1,6 +1,6 @@
 You can join multiple pdf files into one using this command:
 
-```
+```bash
 pdfunite in-1.pdf in-2.pdf in-n.pdf out.pdf
 ```
 

command-line-utils/splitting-pdf-files.md

@@ -1,6 +1,6 @@
 You can extract certain parts of a pdf file with this:
 
-```
+```bash
 pdfjam original.pdf 5-10 -o out.pdf
 ```
 

command-line-utils/virtual-environment-with-system-packages.md

@@ -1,4 +1,4 @@
 You can use below command to create a virtual environment which contains installed packages:
-```
+```bash
 virtualenv venv --system-site-packages
 ```