Add pgmonitor-extension by CrunchyData (#789)

contrib/pgmonitor/Dockerfile

@@ -0,0 +1,15 @@
+# Set PostgreSQL version
+ARG PG_VERSION=15
+FROM quay.io/coredb/c-builder:pg${PG_VERSION}
+
+# Clone repository
+RUN git clone https://github.com/CrunchyData/pgmonitor-extension.git
+
+# Set project version
+ARG EXTENSION_VERSION
+
+# Build extension
+RUN cd pgmonitor-extension && \
+    git fetch origin v${EXTENSION_VERSION} && \
+    git checkout v${EXTENSION_VERSION} && \
+    make

contrib/pgmonitor/Trunk.toml

@@ -0,0 +1,16 @@
+[extension]
+name = "pgmonitor"
+version = "2.0.0"
+repository = "https://github.com/CrunchyData/pgmonitor-extension.git"
+license = "Apache-2.0"
+description = "PostgreSQL extension that provides a means to collect metrics that can be used by an external collection source."
+documentation = "https://github.com/CrunchyData/pgmonitor-extension.git"
+categories = ["metrics"]
+
+[build]
+postgres_version = "15"
+platform = "linux/amd64"
+dockerfile = "Dockerfile"
+install_command = """
+    cd pgmonitor-extension && make install
+    """