Using echo instead of cat is a bit complicated for beginners

[linghengqian]

Summary

• Using echo instead of cat is a bit complicated for beginners. See https://buildpacks.io/docs/for-buildpack-authors/tutorials/basic-buildpack/07_make-buildpack-configurable/ .
• I think the following snippet,

plan=${CNB_BUILD_PLAN_PATH}
version=3.1.3

if [[ -f .node-js-version ]]; then
    version=$(cat .node-js-version | tr -d '[:space:]')
fi

echo "provides = [{ name = \"node-js\" }]" > "$plan"
echo "requires = [{ name = \"node-js\", metadata = { version = \"$version\" } }]" >> "$plan"

• It should be changed to,

version=3.1.3

if [[ -f .node-js-version ]]; then
    version=$(< .node-js-version tr -d '[:space:]')
fi

cat > "${CNB_BUILD_PLAN_PATH}" << EOL
provides = [{ name = "node-js" }]
requires = [{ name = "node-js", metadata = { version = "$version" } }]
EOL

• This will avoid IntelliJ IDEA warnings.
• 

What questions should this documentation answer?

• Null.

Who is the target audience for this documentation?

• App Developer
• Buildpack Author
• Operator
• Other:

Additional Information

• Originated from Creating Cloud Native Buildpacks for ShardingSphere Agent apache/shardingsphere#32947 .

[linghengqian]

• I will submit a PR for this.