ci(docs) replace use of sed with proper configuration variables

docs/overview/renderers/arm-2d.md

@@ -1,6 +1,4 @@
 ```eval_rst
-.. include:: /header.rst
-:github_url: |github_link_base|/overview/renderers/arm-2d.md
 ```
 # ARM-2D GPU
 

docs/overview/renderers/dma2d.md

@@ -1,6 +1,4 @@
 ```eval_rst
-.. include:: /header.rst
-:github_url: |github_link_base|/overview/renderers/dma2d.md
 ```
 # DMA2D GPU
 

docs/overview/renderers/index.md

@@ -1,6 +1,4 @@
 ```eval_rst
-.. include:: /header.rst
-:github_url: |github_link_base|/overview/renderers/index.md
 ```
 
 # Renderers and GPUs

docs/overview/renderers/pxp-vglite.md

@@ -1,6 +1,4 @@
 ```eval_rst
-.. include:: /header.rst
-:github_url: |github_link_base|/overview/renderers/pxp-vglite.md
 ```
 # NXP PXP and VGLite GPU
 

docs/overview/renderers/sdl.md

@@ -1,6 +1,4 @@
 ```eval_rst
-.. include:: /header.rst
-:github_url: |github_link_base|/overview/renderers/sdl.md
 ```
 # SDL renderer
 

docs/overview/renderers/sw.md

@@ -1,6 +1,4 @@
 ```eval_rst
-.. include:: /header.rst
-:github_url: |github_link_base|/overview/renderers/sw.md
 ```
 # Software renderer