Docs: How to contribute new theme (#5863)

* Update 05_Configuration.md

* Update 11_Themes.md

* Update contributing.md

* Update 02_Design.md

* fix

---------

Co-authored-by: math-gh <>

1 files changed, 12 insertions, 8 deletions

diff --git a/docs/en/developers/04_Frontend/02_Design.md b/docs/en/developers/04_Frontend/02_Design.md
index a497ac29d..fb1496985 100644
--- a/docs/en/developers/04_Frontend/02_Design.md
+++ b/docs/en/developers/04_Frontend/02_Design.md
@@ -4,14 +4,14 @@
 
 **As of writing (02-02-2021), support for themes as extensions is under development.**
 
-The easiest way to create a theme is by copying and modifying the base theme (or another of the pre-installed themes). The base theme can be found in [/p/themes/base-theme](https://github.com/FreshRSS/FreshRSS/tree/edge/p/themes/base-theme). Themes require:
+The easiest way to create a theme is by copying and modifying the base theme (or another of the pre-installed themes). The base theme can be found in [/p/themes/base-theme](https://github.com/FreshRSS/FreshRSS/tree/edge/p/themes/base-theme). Each Theme requires:
 
-- a **metadata.json** file to describe the theme.
-- a **loader.gif** file to use as a loading icon (assuming .loading’s background has not been overridden)
-- an **icons** folder containing .svg, .ico, and .png files to override existing icons
-- a **thumbs** folder containing a file, **original.png** that will be used as the preview for the theme
+- a `metadata.json` file to describe the theme
+- a `loader.gif` file to use as a loading icon
+- an (optional) `icons` folder containing .svg (for icons), .ico (for favicons), and .png (for special cases) files to override existing icons
+- a `thumbs` folder containing a file, `original.png` that will be used as the preview for the theme
 
-"_frss.css" is normally added to the metadata file as a fallback for missing aspects. The file is taken from the base theme. If submitting a pull request for a theme, please know that [pull request themes must include this file.](https://github.com/FreshRSS/FreshRSS/pull/2938#issuecomment-624085450)
+`_frss.css` is normally added to the `metadata.json` file as a fallback for missing aspects or as basement. The file is taken from the base theme.
 
 ## RTL Support
 
@@ -19,7 +19,7 @@ RTL (right-to-left) support for languages such as Hebrew and Arabic is handled t
 
 ## Overriding icons
 
-To replace the default icons, add an "icons" folder to your theme’s folder. Use files with the same name as the default icon to override them.
+To replace the default icons, add an `icons` folder to your theme’s folder. Use files with the same name as the default icon to override them.
 
 ## Template file
 
@@ -35,4 +35,8 @@ To replace the default icons, add an "icons" folder to your theme’s folder. Us
 }
 ```
 
-An example of a css theme file can be found at [/p/themes/base-theme/base.css](https://github.com/FreshRSS/FreshRSS/blob/edge/p/themes/base-theme/base.css)
+An example of a CSS theme file can be found at [/p/themes/base-theme/base.css](https://github.com/FreshRSS/FreshRSS/blob/edge/p/themes/base-theme/base.css)
+
+## Installation
+
+see [](../../admins/11_Themes.md)