Sync Masonry's `.gitignore` with the repo's `.gitignore`. (#272)

The general editor/OS ignore filters are useful across the repo.

Fixees one of the Masonry specific snapshot filters, which was broken
due to a copy-paste accident.

.gitignore

@@ -1,8 +1,2 @@
-## Rust
-target/
-# We're a library, so ignore Cargo.lock
-Cargo.lock
-
-.vscode
-.cspell
+/target
 .DS_Store

crates/masonry/.gitignore

@@ -1,35 +1,3 @@
-## Rust build files
-target/
-
-## Intellij Idea
-.idea/
-
-## Visual Studio Code
-.vscode/
-
-## Sublime Text
-*.sublime-workspace
-*.sublime-project
-
-## Vim
-tags
-Session.vim
-Sessionx.vim
-
-## macOS
-.DS_Store
-.AppleDouble
-.LSOverride
-
-## Windows
-Thumbs.db
-ehthumbs.db
-ehthumbs_vista.db
-*.lnk
-
-## Linux
-*~
-
 # Visual snapshots
 **/screenshots/*.diff.png
-**/screenshots/*.new.png## Rust
+**/screenshots/*.new.png