Fixes to C++ and Python OTel codelabs (#35)

Author: yashykt

codelabs/grpc-cpp-opentelemetry/README.md

@@ -38,6 +38,7 @@ $ cp bazelisk-linux-amd64 /usr/local/bin/bazel
 ### **What you’ll need**
 
 * A computer with internet connection
+* Ability to open three separate terminals.
 
 <!-- TODO(yashkt/arvindbright) : Add some additional boilerplate stuff over here if needed. -->
 
@@ -95,7 +96,7 @@ int main(int argc, char** argv) {
 ```
 
 > [!NOTE]
-> How a Prometheus Exporter is being set up on the OpenTelemetry Meter Provider.
+> A Prometheus Exporter is being set up on the OpenTelemetry Meter Provider.
 > (There are other ways to export the metrics as well. This codelab chooses the
 > prometheus exporter.) This MeterProvider is provided to gRPC’s OpenTelemetry
 > plugin as configuration. Once the OpenTelemetry plugin is registered globally

codelabs/grpc-python-opentelemetry/README.md

@@ -33,7 +33,7 @@ $ python -m pip install --upgrade pip
 #### Install dependencies
 
 ```console
-$ cd codelabs/gRPC_Python_OpenTelemetry_Plugin/
+$ cd codelabs/grpc-python-opentelemetry/
 $ python -m pip install -r requirements.txt
 ```
 
@@ -47,6 +47,7 @@ $ python -m pip install -r requirements.txt
 ### **What you’ll need**
 
 * A computer with internet connection
+* Ability to open three separate terminals.
 
 ## Instrumenting applications with gRPC OpenTelemetry Plugin 
 
@@ -67,6 +68,9 @@ import helloworld_pb2_grpc
 from opentelemetry.exporter.prometheus import PrometheusMetricReader
 from opentelemetry.sdk.metrics import MeterProvider
 from prometheus_client import start_http_server
+
+_SERVER_PORT = "50051"
+_PROMETHEUS_PORT = 9465
 ```
 
 Then transform `run()` to look like