enter beta mode and fix typo (#321)

### Description

Merging this pr will automatically create a Version Packages Beta pr
which we will then merge to release betas of all packages that get an
update

### Other changes

typo in command it is singular not plural

<!-- start pr-codex -->

---

## PR-Codex overview
This PR updates the initial versions of various packages to prepare for
a beta release.

### Detailed summary
- Updated initial versions for multiple packages in
`.changeset/pre.json`
- Added `"mode": "pre"` and `"tag": "beta"` to the changeset metadata

> ✨ Ask PR-Codex anything about this PR by commenting with `/codex {your
question}`

<!-- end pr-codex -->

.changeset/pre.json

@@ -0,0 +1,30 @@
+{
+  "mode": "pre",
+  "tag": "beta",
+  "initialVersions": {
+    "@celo/celocli": "5.1.0",
+    "@celo/dev-utils": "0.0.4",
+    "@celo/base": "6.1.0",
+    "@celo/connect": "6.0.0",
+    "@celo/contractkit": "8.1.0",
+    "@celo/cryptographic-utils": "5.1.0",
+    "@celo/explorer": "5.0.11",
+    "@celo/governance": "5.1.2",
+    "@celo/keystores": "5.0.10",
+    "@celo/network-utils": "5.0.6",
+    "@celo/phone-utils": "6.0.3",
+    "@celo/transactions-uri": "5.0.10",
+    "@celo/utils": "7.0.0",
+    "@celo/wallet-base": "6.0.0",
+    "@celo/wallet-hsm": "6.0.0",
+    "@celo/wallet-hsm-aws": "6.0.0",
+    "@celo/wallet-hsm-azure": "6.0.0",
+    "@celo/wallet-hsm-gcp": "6.0.0",
+    "@celo/wallet-ledger": "6.0.0",
+    "@celo/wallet-local": "6.0.0",
+    "@celo/wallet-remote": "6.0.0",
+    "@celo/wallet-rpc": "6.0.0",
+    "@celo/typescript": "0.0.1"
+  },
+  "changesets": []
+}

RELEASE.md

@@ -70,7 +70,7 @@ and publish GitHub release notes.
 
 from master checkout a new branch (name as you wish) and run 
 
-`yarn changesets pre enter beta`
+`yarn changeset pre enter beta`
 
 This will create `.changeset/pre.json`