docs: update installation docs for linux - pango (#1060)

* Linux users should install Pango also

see ManimCommunity/ManimPango#27
manylinux wheels are to be removed in next release on ManimPango

* Add changes to Docker also

* don't mix tabs and spaces

Author: naveen521kk

docker/Dockerfile

@@ -6,6 +6,7 @@ RUN apt-get update -qq \
         gcc \
         libcairo2-dev \
         libffi-dev \
+        libpango1.0-dev \
         pkg-config \
         wget
 

docs/source/installation/linux.rst

@@ -26,6 +26,12 @@ To install cairo:
 
    sudo apt install libcairo2-dev
 
+To install Pango:
+
+.. code-block:: bash
+
+   sudo apt install libpango1.0-dev
+
 To install ffmpeg:
 
 .. code-block:: bash
@@ -58,6 +64,12 @@ To install cairo:
 
   sudo dnf install cairo-devel
 
+To install Pango:
+
+.. code-block:: bash
+
+   sudo dnf install pango-devel
+
 To install ffmpeg, you have to add RPMfusion repository (If it's not already added). Please follow the instructions for your specific distribution in the following URL:
 
 https://rpmfusion.org/Configuration/
@@ -96,6 +108,11 @@ To install cairo:
 
    sudo pacman -S cairo
 
+To install pango:
+
+.. code-block:: bash
+
+   sudo pacman -S pango
 
 To install ffmpeg: