fix: -broadcast true in doc (#1288)

<!-- please provide a detailed description of the changes made in this
pull request. -->

<details><summary>Contributors' checklist...</summary>

- [ ] Added new tests, or not needed, or not feasible
- [ ] Provided an example (e.g. screenshot) to aid review or the PR is
self-explanatory
- [ ] Updated the official documentation or not needed
- [ ] No breaking changes were made, or a `BREAKING CHANGE: xxx` message
was included in the description
- [ ] Added references to related issues and PRs
- [ ] Provided any useful hints for running manual tests
- [ ] Added new benchmarks to [generated
graphs](https://gnoland.github.io/benchmarks), if any. More info
[here](https://github.com/gnolang/gno/blob/master/.benchmarks/README.md).
</details>

examples/gno.land/r/demo/groups/README.md

@@ -8,7 +8,7 @@
 
 ### - create group
 
-    ./build/gnokey maketx call -func "CreateGroup" -args "dao_trinity_ngo" -gas-fee "1000000ugnot" -gas-wanted 4000000 -broadcast true -chainid dev -remote 0.0.0.0:26657 -pkgpath "gno.land/r/demo/groups" test1 
+    ./build/gnokey maketx call -func "CreateGroup" -args "dao_trinity_ngo" -gas-fee "1000000ugnot" -gas-wanted 4000000 -broadcast -chainid dev -remote 0.0.0.0:26657 -pkgpath "gno.land/r/demo/groups" test1 
 
 ### - add member