[elpa] externals/diff-hl 6cb0d2774f 1/2: Mention that VC must be enabled

[ELPA Syncer]

branch: externals/diff-hl
commit 6cb0d2774f8806dbd011b8b3c15b291b39217837
Author: Radon Rosborough <radon.neon@gmail.com>
Commit: GitHub <noreply@github.com>

    Mention that VC must be enabled
    
    Some people disable VC because it fixes various oddities in Emacs and
    the same features are provided by other packages such as Magit. In
    this case, diff-hl will silently do nothing, which is confusing. This
    PR adds a note to the README clarifying the requirements for using
    diff-hl.
---
 README.md | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/README.md b/README.md
index 4029dff219..d1b3979e01 100644
--- a/README.md
+++ b/README.md
@@ -34,6 +34,9 @@ Put this into your init script:
 (global-diff-hl-mode)
 ```
 
+You must also ensure that VC is enabled (e.g. `vc-handled-backends` is
+not nil).
+
 Check out the Commentary section in each file for more detailed usage
 instructions.