Moved example to examples directory [skip ci]

Author: ankane

.github/workflows/build.yml

@@ -17,4 +17,4 @@ jobs:
           make
           sudo make install
       - run: zig build
-      - run: zig-out/bin/example
+      - run: zig-out/bin/libpq

README.md

@@ -58,7 +58,7 @@ const res = pg.PQexec(conn, "CREATE INDEX ON items USING ivfflat (embedding vect
 
 Use `vector_ip_ops` for inner product and `vector_cosine_ops` for cosine distance
 
-See a [full example](example.zig)
+See a [full example](examples/libpq.zig)
 
 ## Contributing
 
@@ -76,7 +76,7 @@ git clone https://github.com/pgvector/pgvector-zig.git
 cd pgvector-zig
 createdb pgvector_zig_test
 zig build
-zig-out/bin/example
+zig-out/bin/libpq
 ```
 
 Specify the path to libpq if needed:

build.zig

@@ -1,14 +1,12 @@
 const std = @import("std");
 
 pub fn build(b: *std.Build) void {
-    const exe = b.addExecutable(.{
-        .name = "example",
-        .root_source_file = b.path("example.zig"),
+    const libpqExe = b.addExecutable(.{
+        .name = "libpq",
+        .root_source_file = b.path("examples/libpq.zig"),
         .target = b.graph.host,
     });
-
-    exe.linkSystemLibrary("pq");
-    exe.linkLibC();
-
-    b.installArtifact(exe);
+    libpqExe.linkSystemLibrary("pq");
+    libpqExe.linkLibC();
+    b.installArtifact(libpqExe);
 }