Escape "<Leader>" references

... so they display properly when the markdown is rendered (e.g. on the GitHub page)

README.md

@@ -5,10 +5,10 @@ BufExplorer Plugin for Vim
 
 With bufexplorer, you can quickly and easily switch between buffers by using the one of the default public interfaces:
 
-  '<Leader>be' (normal open)  or
-  '<Leader>bt' (toggle open / close)  or
-  '<Leader>bs' (force horizontal split open)  or
-  '<Leader>bv' (force vertical split open)
+  '\<Leader\>be' (normal open)  or
+  '\<Leader\>bt' (toggle open / close)  or
+  '\<Leader\>bs' (force horizontal split open)  or
+  '\<Leader\>bv' (force vertical split open)
 
 Once the bufexplorer window is open you can use the normal movement keys (hjkl) to move around and then use <Enter> or <Left-Mouse-Click> to select the buffer you would like to open. If you would like to have the selected buffer opened in a new tab, simply press either <Shift-Enter> or 't'. Please note that when opening a buffer in a tab, that if the buffer is already in another tab, bufexplorer can switch to that tab automatically for you if you would like. More about that in the supplied VIM help.