[pitivi] docs/releases/0.99{,9}.md: Fix incorrect md syntax

[Alexandru Băluț <alexbalut src gnome org>]

commit d1ac6b2ee4d9ce187a2cfe782af62107a77a1b3d
Author: Jona <jdemeyer hotmail com>
Date:   Sat Sep 8 04:50:29 2018 +0200

    docs/releases/0.99{,9}.md: Fix incorrect md syntax

 docs/releases/0.99.md  | 2 +-
 docs/releases/0.999.md | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)
---
diff --git a/docs/releases/0.99.md b/docs/releases/0.99.md
index 6daf3128..bfd9548a 100644
--- a/docs/releases/0.99.md
+++ b/docs/releases/0.99.md
@@ -5,7 +5,7 @@ first [Pitivi 1.0][1.0.md] release candidate.
 
 This release includes many bug fixes.
 
-== Contributors for this release ==
+## Contributors for this release
 
 Pitivi:
 
diff --git a/docs/releases/0.999.md b/docs/releases/0.999.md
index 794ab780..2272f9ae 100644
--- a/docs/releases/0.999.md
+++ b/docs/releases/0.999.md
@@ -18,7 +18,7 @@ on the right side.
 
 This release includes many bug fixes.
 
-== Contributors for this release ==
+## Contributors for this release
 
 Pitivi: