add automatic external link icon using CSS

Signed-off-by: Michel-FK <michel.stempin@funkey-project.com>

docs/tutorials/hardware/change_sd_card.md

@@ -10,17 +10,17 @@ your data.
 ## Download the latest FunKey-OS image file
 
 Get the latest "***FunKey-rootfs-x.y.z.img***" SD card image file
-directly from [here:fontawesome-solid-external-link-alt:][1] or from
-the bottom of the latest release page in the "assets" section:
+directly from [here][1] or from the bottom of the latest release page
+in the "assets" section:
 
-[https://github.com/FunKey-Project/FunKey-OS/releases/latest:fontawesome-solid-external-link-alt:][2]{target=_blank}
+[https://github.com/FunKey-Project/FunKey-OS/releases/latest][2]{target=_blank}
 
 ![Github Release](/assets/images/github_sd_card_image.png){.lightbox}
 
 ## Flash the micro-SD card with balenaEtcher
 
 - Download and install balenaEtcher for Windows/Mac OS/Linux from
-  [balena.io:fontawesome-solid-external-link-alt:][3]{:target="blank"}
+  [balena.io][3]{target=_blank}
 
 - Run balenaEtcher and click on "Flash from file" to select the
   FunKey-OS image file

docs/tutorials/software/add_roms.md

@@ -4,13 +4,10 @@ Yes legally! Despite the general opinion, it is perfectly possible to
 purchase and play famous ROMs legally such as Sonic, Castlevania,
 Megaman and more, read the note below for more details.
 
-**The FunKey Wiki** maintains
-[lists:fontawesome-solid-external-link-alt:][1]{target=_blank} of
-legal sources for ROMs, including [freeware
-ROMs:fontawesome-solid-external-link-alt:][2]{target=_blank},
-[commercial
-ROMs:fontawesome-solid-external-link-alt:][3]{target=_blank}, and
-[utilities:fontawesome-solid-external-link-alt:][4]{target=_blank}.
+**The FunKey Wiki** maintains [lists][1]{target=_blank} of legal
+sources for ROMs, including [freeware ROMs][2]{target=_blank},
+[commercial ROMs][3]{target=_blank}, and
+[utilities][4]{target=_blank}.
 
 !!! note "Note about ROM emulation"
 
@@ -29,7 +26,7 @@ ROMs:fontawesome-solid-external-link-alt:][3]{target=_blank}, and
     retro-games online as ROMs.
 
     For example, it is perfectly legal to purchase the SEGA Mega Drive
-    and Genesis Classics on [Steam][5]{:target="blank"} and play Sonic
+    and Genesis Classics on [Steam][5]{target=_blank} and play Sonic
     on your **FunKey S**.
 
 # Add ROMs to the FunKey S

docs/tutorials/software/copy_opk.md

@@ -8,11 +8,9 @@ does not require installation to be able to run them.
     In the current (2.0.0) release of the FunKey-OS, the **OPK** files
     are only available for the gmenu2x launcher, and not in RetroFE.
 
-[7-Zip:fontawesome-solid-external-link-alt:][1] can be used to extract
-**OPK** files, and [Open Package Creator
-(v1.1.2):fontawesome-solid-external-link-alt:][2] is a useful tool if
-you want to re-package an **OPK** or customize icons, add additional
-games and much more.
+[7-Zip][1] can be used to extract **OPK** files, and [Open Package
+Creator (v1.1.2)][2] is a useful tool if you want to re-package an
+**OPK** or customize icons, add additional games and much more.
 
 Connect your **FunKey S** console to your computer and add **OPK**
 files as simply as you would do it with a simple USB memory stick:

docs/tutorials/software/gb_palette.md

@@ -1,9 +1,8 @@
 # Palette description
 
-The default **FunKey S** Game Boy emulator:
-_[gnuboy:fontawesome-solid-external-link-alt:][1]_ allows to set the
-palette used for grayscale when running DMG (original mono Gameboy)
-ROMs.
+The default **FunKey S** Game Boy emulator: _[gnuboy][1]_ allows to
+set the palette used for grayscale when running DMG (original mono
+Gameboy) ROMs.
 
 There are four variables for this purpose, allowing the background,
 window, and both sprite palettes to be colored differently. Each one

docs/tutorials/software/update.md

@@ -2,10 +2,10 @@ A firmware upgrade can be performed simply over USB without opening
 the **FunKey S** console.
 
 Get the latest "**_FunKey-rootfs-x.y.z.fwu_**" firmware update file
-directly from [here:fontawesome-solid-external-link-alt:][1] or from
-the bottom of the latest release page in the "assets" section:
+directly from [here][1] or from the bottom of the latest release page
+in the "assets" section:
 
-[https://github.com/FunKey-Project/FunKey-OS/releases/latest:fontawesome-solid-external-link-alt:][2]{target=_blank}
+[https://github.com/FunKey-Project/FunKey-OS/releases/latest][2]{target=_blank}
 
 ![Github Release](/assets/images/Github_Release.png){.lightbox}