Remove .bin from git files, move folder creation to script

.gitignore

@@ -1,5 +1,4 @@
-/tinygo
-/.bin/*
+/.bin
 *.gz
 *.br
 *.zst

build-wasm.sh

@@ -5,6 +5,8 @@ set -o pipefail
 
 cd "$(cd -P -- "$(dirname -- "${BASH_SOURCE[0]}")" && pwd -P)"
 
+mkdir -p .bin/ 2>/dev/null
+
 # Setup tinygo first
 if [[ ! -d .bin/tinygo ]]; then
   git clone --depth=1 --branch v0.37.0 https://github.com/tinygo-org/tinygo.git .bin/tinygo