doc: Move client hints to Wiki

[why]
The main readme is already too big anyhow.
We should extract topics into sub-pages rather than adding more.

[how]
Use the Wiki instead and link the Wiki clearly, with entries in the TOC.

Signed-off-by: Fini Jastrow <ulf.fini.jastrow@desy.de>

readme.md

@@ -61,6 +61,7 @@ The following flow diagram shows the current glyph sets included:
 [**Project Motivation**](#project-motivation)
 
 **Additional Info**
+  * [**In case of problems**](#common-problems)
   * [**Unstable file paths on master**](#unstable-file-paths)
   * [**Changelog**](#changelog)
   * [**License**](#license)
@@ -107,14 +108,6 @@ See [Wiki: Glyph Sets and Codepoints for more details][wiki-glyph-sets-codepoint
 
 See [Wiki: Icon names in shell][wiki-icon-names-in-shell]
 
-### Displaying Private Use Area (PUA) Characters in `less`
-
-If you are using `less` (version 633 or above) and notice that Private Use Area (PUA) characters from Nerd Fonts are not displaying, you can use the `LESSUTFCHARDEF` environment variable to specify the code points for PUA characters. This can be done as follows:
-
-```bash
-export LESSUTFCHARDEF=23fb-23fe:p,2665:p,26a1:p,2b58:p,e000-e00a:p,e0a0-e0a2:p,e0a3:p,e0b0-e0b3:p,e0b4-e0c8:p,e0ca:p,e0cc-e0d4:p,e200-e2a9:p,e300-e3e3:p,e5fa-e6a6:p,e700-e7c5:p,ea60-ebeb:p,f000-f2e0:p,f300-f32f:p,f400-f532:p,f500-fd46:p,f0001-f1af0:p
-```
-
 ## Patched Fonts
 
 A preview of all fonts can be found [here](https://www.nerdfonts.com/font-downloads).
@@ -594,6 +587,13 @@ Usage: ./gotta-patch-em-all-font-patcher!.sh [OPTION] [FILTER]
 
 See [contributing.md](contributing.md)
 
+## Common Problems
+
+Some solutions can be found on the Wiki, if you are lucky. For example hints to use the pager `less` are there:
+
+* https://github.com/ryanoasis/nerd-fonts/wiki/FAQ-and-Troubleshooting
+* https://github.com/ryanoasis/nerd-fonts/wiki/Terminal-Emulators
+* https://github.com/ryanoasis/nerd-fonts/wiki/Reporting-Issues
 
 ## Unstable File Paths