[Setup] Add build phases for copying README and source code files

[yo1995]

Description

This PR adds 2 build phases to the project file

• Copy Source Code Files
• Copy README.md Files For Source Code View

so that the README and Swift source code files can be accessed in the bundle, to be shown in the source code and README view in the app.

Linked Issue(s)

• common-samples/issues/3704
• https://github.com/ArcGIS/arcgis-runtime-samples-swift/projects/1#card-81545305
• Copy READMEs into a single directory arcgis-runtime-samples-ios#812
• [Setup] Content Display Logic #2 (comment)

How To Test

This is the preparation for the cs-3704 mini project.

To Discuss

The shell script to copy READMEs

This script copies all the READMEs to the bundle's root folder: Samples.app/READMEs/{sample_name}

(i.e. Bundle.main.url(forResource: "name", withExtension: "md", subdirectory: "READMEs")!)

echo $BUILT_PRODUCTS_DIR

# Directory to which the readmes will be copied.
READMES_DIR=${BUILT_PRODUCTS_DIR}/${CONTENTS_FOLDER_PATH}/READMEs
mkdir -p "${READMES_DIR}"

# Root readme for the project to skip.
DEFAULT_README=$SRCROOT/README.md

# Find all README.md files in the project.
find ${SRCROOT} -name "README.md" | while read file
do
    # Skip the root readme for project.
    if [ "$file" = "$DEFAULT_README" ]
    then
        echo $BUILT_PRODUCTS_DIR
        continue
    fi
    
    # Extract the folder name from the path.
    FILE_PATH=$(dirname "$file")
    FOLDER_NAME=$(basename "$FILE_PATH")
    
    cp "${file}" "${READMES_DIR}/${FOLDER_NAME}.md"
done