[epiphany] gitignore: add usual meson build directory

[Michael Catanzaro <mcatanzaro src gnome org>]

commit d3073cae93032509ef45b6c8a725fd83c44e9a2f
Author: vanadiae <vanadiae35 gmail com>
Date:   Tue May 19 20:27:02 2020 +0200

    gitignore: add usual meson build directory
    
    Currently, the only item in the gitignore is build/
    
    However, every usual tool (gnome builder, etc)puts its build
    output to _build/ and so when selecting files to commit in a GUI
    for git, there is a bunch of _build/* files that hides the real
    files that you might want to commit.
    
    So change to the commonly used build directory _build/

 .gitignore | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/.gitignore b/.gitignore
index 567609b12..69fa449dd 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1 +1 @@
-build/
+_build/