[borg] Rewrite include/exclude notes to match docs

examples/example.borg

@@ -39,20 +39,11 @@
 # keepmonthly = -1
 
 ## A few notes about includes and excludes:
-## 1. include, exclude statements support globbing with '*'
-## 2. Symlinks are not dereferenced. Moreover, an include line whose path
-##    contains, at any level, a symlink to a directory, will only have the
-##    symlink backed-up, not the target directory's content. Yes, you have to
-##    dereference yourself the symlinks, or to use 'mount --bind' instead.
-##    Example: let's say /home is a symlink to /mnt/crypt/home ; the following
-##    line will only backup a "/home" symlink ; neither /home/user nor
-##    /home/user/Mail will be backed-up :
-##      include = /home/user/Mail
-##    A workaround is to 'mount --bind /mnt/crypt/home /home' ; another one is to
-##    write :
-##      include = /mnt/crypt/home/user/Mail
-## 3. All the excludes come after all the includes. The order is not otherwise
-##    taken into account.
+## 1. include paths do not support any kind of pattern matching
+## 2. exclude paths support several types of pattern matching, the default being
+##    shell-style matching, where, for example, '*' matches any number of
+##    characters. for more info, see : borg help patterns
+## 3. Symlinks are preserved (not followed).
 
 ## files to include in the backup
 include = /opt