Fix RC tags in docs (#2239)

VERSIONING.md

@@ -150,10 +150,10 @@ The `otel` package is refactored to remove its dependencies on `otel/metric` so
 it can be released as stable as well. With that done the following release
 candidates are made:
 
-* `otel`: `v1.0.0-rc.1`
-* `otel/trace`: `v1.0.0-rc.1`
-* `otel/baggage`: `v1.0.0-rc.1`
-* `otel/sdk/trace`: `v1.0.0-rc.1`
+* `otel`: `v1.0.0-RC1`
+* `otel/trace`: `v1.0.0-RC1`
+* `otel/baggage`: `v1.0.0-RC1`
+* `otel/sdk/trace`: `v1.0.0-RC1`
 
 The `otel/metric` and `otel/sdk/metric` modules remain at `v0.14.0`.
 
@@ -161,10 +161,10 @@ A few minor issues are discovered in the `otel/trace` package. These issues are
 resolved with some minor, but backwards incompatible, changes and are released
 as a second release candidate:
 
-* `otel`: `v1.0.0-rc.2`
-* `otel/trace`: `v1.0.0-rc.2`
-* `otel/baggage`: `v1.0.0-rc.2`
-* `otel/sdk/trace`: `v1.0.0-rc.2`
+* `otel`: `v1.0.0-RC2`
+* `otel/trace`: `v1.0.0-RC2`
+* `otel/baggage`: `v1.0.0-RC2`
+* `otel/sdk/trace`: `v1.0.0-RC2`
 
 Notice that all module version numbers are incremented to adhere to our
 versioning policy.
@@ -205,12 +205,12 @@ As we progress, the `otel/metric` and `otel/sdk/metric` packages have reached a
 point where they should be evaluated for stability. The `otel` module is
 reintegrated with the `otel/metric` package and the following release is made:
 
-* `otel`: `v1.1.0-rc.1`
-* `otel/trace`: `v1.1.0-rc.1`
-* `otel/metric`: `v1.1.0-rc.1`
-* `otel/baggage`: `v1.1.0-rc.1`
-* `otel/sdk/trace`: `v1.1.0-rc.1`
-* `otel/sdk/metric`: `v1.1.0-rc.1`
+* `otel`: `v1.1.0-RC1`
+* `otel/trace`: `v1.1.0-RC1`
+* `otel/metric`: `v1.1.0-RC1`
+* `otel/baggage`: `v1.1.0-RC1`
+* `otel/sdk/trace`: `v1.1.0-RC1`
+* `otel/sdk/metric`: `v1.1.0-RC1`
 
 All the modules are evaluated and determined to a viable stable release. They
 are then released as version `v1.1.0` (the minor version is incremented to