shell: added enter error

wiki/games/steam.md

@@ -72,7 +72,8 @@ used the
 [user space configuration](../syncthing.md#user-space-configuration-for-linux)
 is recommended.
 Afterwards move the game saves to the directory set up by Syncthing and create
-symbolic links to link them back to the original place.
+[symbolic links](/wiki/linux/shell.md#symbolic-links-using-ln) to link them back to the original
+place.
 
 ## Error Handling
 

wiki/linux/shell.md

@@ -24,6 +24,17 @@ The following is a list of Unix shells that are POSIX compliant.
 This section addresses various different functions by and actions that can be
 taken with shell commands.
 
+### Symbolic Links using `ln`
+
+`ln` is a command to create links between files and folders.
+The most simple way to create a link between two folders or files is running the following
+command.
+Replace `<source folder/file>` and `<target folder/file>` as needed.
+
+```sh
+ln -s <source folder/file> <target folder/file>
+```
+
 ### `ls` and its Alternatives
 
 `ls` is a command to list files and directories.
@@ -178,3 +189,16 @@ Error outputs (stderr) can be silenced by appending `2> /dev/null`.
 The complete output of both stderr and stdout can be silenced by appending
 `> /dev/null 2>&1` to the command.
 A shortened version of it not possible on all shells is `&> /dev/null`.
+
+## Error solving
+
+This section addresses various problems that can occur and are related to the shell.
+
+### Pressing Enter Produces `^M`
+
+This error can easily be fixed by running the following command.
+It is related to a terminal line setting problem.
+
+```sh
+stty sane
+```