chore: gitignore .yalc/ and yalc.lock (#159)

Prevents yalc artifacts from being accidentally committed. Any
developer following the README's yalc workflow will generate these
files during local consumer testing.

Author: rickstaa

.gitignore

@@ -5,6 +5,8 @@
 /.pnp
 .pnp.js
 .yarn/cache/
+.yalc/
+yalc.lock
 
 # testing
 /coverage
@@ -39,4 +41,4 @@ yarn-error.log*
 
 /dist
 
-.parcel-cache
+.parcel-cache