Description how to get release: use standard shell tools.

Don't put the user through the hassle to first have to install
some scripting language when they can use common tools available
in any shell.

Also set 'silent' flag on curl to adhere to the no-news-are-good-news
Unix principle.

PiperOrigin-RevId: 642802671

README.md

@@ -78,11 +78,11 @@ The following downloads the latest github repo release binaries for an x64 Linux
 
 ```bash
 # Determine the url of the latest release tarball.
-LATEST_XLS_RELEASE_TARBALL_URL=$(curl -L \
+LATEST_XLS_RELEASE_TARBALL_URL=$(curl -s -L \
   -H "Accept: application/vnd.github+json" \
   -H "X-GitHub-Api-Version: 2022-11-28" \
   https://api.github.com/repos/google/xls/releases | \
-  python3 -c 'import json; import sys; print(json.load(sys.stdin)[0]["assets"][0]["browser_download_url"])')
+  grep -m 1 -o 'https://.*/releases/download/.*\.tar\.gz')
 
 # Download the tarball and unpack it, observe the version numbers for each of the included tools.
 curl -O -L ${LATEST_XLS_RELEASE_TARBALL_URL}

docs_src/README.md

@@ -74,11 +74,11 @@ The following downloads the latest github repo release binaries for an x64 Linux
 
 ```bash
 # Determine the url of the latest release tarball.
-LATEST_XLS_RELEASE_TARBALL_URL=$(curl -L \
+LATEST_XLS_RELEASE_TARBALL_URL=$(curl -s -L \
   -H "Accept: application/vnd.github+json" \
   -H "X-GitHub-Api-Version: 2022-11-28" \
   https://api.github.com/repos/google/xls/releases | \
-  python3 -c 'import json; import sys; print(json.load(sys.stdin)[0]["assets"][0]["browser_download_url"])')
+  grep -m 1 -o 'https://.*/releases/download/.*\.tar\.gz')
 
 # Download the tarball and unpack it, observe the version numbers for each of the included tools.
 curl -O -L ${LATEST_XLS_RELEASE_TARBALL_URL}