feat: added self update mechanism (#15)

* feat: Added self update mechanism

* fix: Formatting

* fix: Formatting again

* fix: Arghhh INDENTATION

* feat: Updated readme with new command

* feat: Added shortcut command

* feat: Added more detail to the readme

* feat: Removed the check for the last update file. It seems a bit pointless to delay checking for it, it's curling github so it's not like it's a DDOS concern, and it could be the tool is getting updated often, why delay their updates? It's also just a curl, it's very inexpensive.

* feat: Removed REPO_URL, it was unused

* feat: Reverted version testing change (oops)

* feat: checking for updates timed at 1 hour

* fix: info messages formatting

---------

Co-authored-by: v4n <105587619+v4n00@users.noreply.github.com>

install.sh

@@ -58,8 +58,7 @@ if [[ -x "$(command -v $SCRIPT_NAME)" ]]; then
 
     if [[ $latest_major -gt $installed_major ]]; then
         echo -e "${ORANGE}Warning:${NC} Major version upgrade detected."
-        echo "${ORANGE}!${NC} Check out the changelogs here:"
-        echo "${ORANGE}!${NC} https://github.com/v4n00/h2mm-cli/releases"
+        echo "${ORANGE}Info${NC}: Check out the changelogs here -> https://github.com/v4n00/h2mm-cli/releases"
         echo "The script will proceed to upgrade ${SCRIPT_NAME} to avoid breaking changes."
 
         # find hd2 path