[devhelp] meson: add .gitignore for the build/ directory

[Sébastien Wilmet <swilmet src gnome org>]

commit 57923964a6b8465e42ce8cc6500260421b57da52
Author: Sébastien Wilmet <swilmet gnome org>
Date:   Fri Mar 23 10:52:17 2018 +0100

    meson: add .gitignore for the build/ directory
    
    Jhbuild creates the build/ directory if the following line is in the
    jhbuildrc:
    buildroot = None

 .gitignore |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)
---
diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..567609b
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1 @@
+build/