[#530] Update shell information to connect with readme files

The changes primarily involve modifying the default.nix files in
govtool/frontend and scripts/govtool directories. Specifically, the
adjustments establish a connection between the shell messages and the
pertinent README.md files, offering developers immediate access to
additional insights and details related to the frontend development and
deployment processes, respectively. This enhancement facilitates a more
streamlined and informative user experience within the development
environment, aligning with the goal of ensuring consistent code style
throughout the backend project.

govtool/frontend/default.nix

@@ -15,7 +15,7 @@ project.overrideAttrs (attrs: {
     tput bold
     warn "Welcome to GovTool!" 4
     warn "This is a frontend development shell." 4
-    warn "Read the govtool/frontend/README.md to get more info about this module." 8
+    warn "Read the ${./README.md} to get more info about this module." 8
     rm -rf ./node_modules
     ln -s ${project.out}/libexec/voltaire-voting-app/node_modules ./node_modules
   '';

scripts/govtool/default.nix

@@ -7,7 +7,7 @@ pkgs.mkShell {
     tput bold
     warn "Welcome to GovTool!" 4
     warn "This is a deployment shell." 4
-    warn "Read the scripts/govtool/README.md to get more info about the deployment processes." 8
+    warn "Read the ${./README.md} to get more info about the deployment processes." 8
     case "''${ENVIRONMENT}" in
       "dev")
         warn "Your configuration is set to deploy to DEV environment, you are safe." 2