Add navigation widgets bcd and cdhist

Examples-(fish).md

@@ -1,6 +1,33 @@
 Examples for fish shell
 -----------------------
 
+### Navigation
+
+```
+function fzf-bcd-widget -d 'cd backwards'
+	pwd | awk -v RS=/ '/\n/ {exit} {p=p $0 "/"; print p}' | tac | eval (__fzfcmd) +m --select-1 --exit-0 $FZF_BCD_OPTS | read -l result
+	[ "$result" ]; and cd $result
+	commandline -f repaint
+end
+```
+
+```
+function fzf-cdhist-widget -d 'cd to one of the previously visited location'
+	## Clear non-existent folders from cdhist.
+	set -l buf
+	for i in (seq 1 (count $dirprev))
+		set -l dir $dirprev[$i]
+		if test -d $dir
+			set buf $buf $dir
+		end
+	end
+	set dirprev $buf
+	string join \n $dirprev | tac | sed 1d | eval (__fzfcmd) +m $FZF_CDHIST_OPTS | read -l result
+	[ "$result" ]; and cd $result
+	commandline -f repaint
+end
+```
+
 ### Git
 
 ```
@@ -40,4 +67,4 @@ function fpass -d "Fuzzy-find a Lastpass entry and copy the password"
 
   lpass ls | fzf | string replace -r -a '.+\[id: (\d+)\]' '$1' | xargs lpass show -c --password
 end
-```
+```