chore: Add comments to build script

bin/build.sh

 #!/bin/bash
 
+# Process SVG files
 ./node_modules/.bin/babel-node bin/process-svgs.js
 
+# Create dist directory
 ./node_modules/.bin/rimraf dist
 mkdir dist
+
+# Build icons.json
 ./node_modules/.bin/babel-node bin/build-icons-json.js
+
+# Build SVG sprite
 ./node_modules/.bin/babel-node bin/build-sprite.js
 
+# Create dist/icons directory
 ./node_modules/.bin/rimraf dist/icons
 mkdir dist/icons
+
+# Build SVG icons
 ./node_modules/.bin/babel-node bin/build-svgs.js
 
+# Build JavaScript library
 ./node_modules/.bin/webpack --output-filename feather.js
 ./node_modules/.bin/webpack --output-filename feather.min.js -p