Verify and update OTLP trace exporter documentation

exporters/otlp/otlptrace/README.md

@@ -0,0 +1,30 @@
+# OpenTelemetry-Go OTLP Span Exporter
+
+OpenTelemetry Protocol (OTLP) Span Exporter.
+
+To constructs a new Otlptrace Exporter and starts it:
+
+```
+exp, err := otlptrace.New(ctx, opts...)
+```
+
+## Installation
+
+```
+go get -u go.opentelemetry.io/otel/exporters/otlp/otlptrace
+```
+
+## [`otlptrace`](https://pkg.go.dev/go.opentelemetry.io/otel/exporters/otlp/otlptrace)
+
+`otlptrace` package implements a span exporter that uses a `otlptrace.Client` interface.
+
+`otlptrace.Client` manages connections to the collector, handles the transformation of data into wire format,
+and the transmission of that data to the collector.
+
+## [`otlptracegrpc`](https://pkg.go.dev/go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracegrpc)
+
+The `otlptracegrpc` package implements a gRPC span exporter.
+
+##  [`otlptracehttp`](https://pkg.go.dev/go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracehttp)
+
+The `otlptracehttp` package implements a HTTP span exporter.