docs(readme): add build instructions

Author: abiriadev

README.md

@@ -55,6 +55,146 @@ Parameters = "(" [ Type { "," Type } ] ")" .
 Query = [ "func" ] [ identifier ] Parameters [ Type ] .
 ```
 
+## Build Manually
+
+```sh
+$ git clone https://github.com/abiriadev/goggle && cd goggle
+```
+
+### Build indexer from source and index custom packages
+
+```sh
+$ go run ./cmd/indexer
+# or
+$ go run ./cmd/indexer <space separated list of packages to index>
+```
+
+See help page for more information:
+
+```sh
+Usage of indexer:
+  -f string
+        index format (default "gob")
+  -o string
+        path to save index file
+```
+
+### Build and run REPL
+
+```sh
+$ go run ./cmd/repl
+# or optionally pass a path to index file to use
+$ go run ./cmd/repl <index file to use>
+```
+
+It will then show you a prompt starting with `λ`.
+
+Type any query(like `() bool`) and enter to see the results.
+
+```go
+λ () bool
+func utf8.FullRune() bool       // FullRune reports whether the bytes in p begin with a full UTF-8 encoding of a rune.
+func nettest.TestableAddress() bool     // TestableAddress reports whether address of network is testable on the current platform configuration.
+func nettest.SupportsRawSocket() bool   // SupportsRawSocket reports whether the current session is available to use raw sockets.
+func nettest.SupportsIPv6() bool        // SupportsIPv6 reports whether the platform supports IPv6 networking functionality.
+func nettest.SupportsIPv4() bool        // SupportsIPv4 reports whether the platform supports IPv4 networking functionality.
+func signal.Ignored() bool      // Ignored reports whether sig is currently ignored.
+func slices.Equal() bool        // Equal reports whether two slices are equal: the same length and all elements equal.
+func testenv.OptimizationOff() bool     // OptimizationOff reports whether optimization is disabled.
+func testenv.HasSymlink() bool  // HasSymlink reports whether the current system can use os.Symlink.
+func testenv.HasSrc() bool      // HasSrc reports whether the entire source tree is available under GOROOT.
+```
+
+### Build and run Goggle server
+
+```sh
+$ go run ./cmd/goggle
+```
+
+The default port number is `6099`(L33T or `Gogg`). You can pass `-port` option to change it.
+
+```sh
+Usage of goggle:
+  -port int
+        port number to bind (default 6099)
+```
+
+Try requesting from terminal:
+
+```sh
+$ http :6099/search q='() bool' -v
+
+POST /search HTTP/1.1
+Accept: application/json, */*;q=0.5
+Accept-Encoding: gzip, deflate, br
+Connection: keep-alive
+Content-Length: 15
+Content-Type: application/json
+Host: localhost:6099
+User-Agent: HTTPie/3.2.1
+
+{
+    "q": "() bool"
+}
+
+HTTP/1.1 200 OK
+Access-Control-Allow-Origin: *
+Content-Length: 1970
+Content-Type: text/plain; charset=utf-8
+Date: Tue, 12 Dec 2023 04:12:01 GMT
+
+{
+    "items": [
+        {
+            "sim": 0,
+            "sig": "func utf8.FullRune() bool",
+            "summary": "FullRune reports whether the bytes in p begin with a full UTF-8 encoding of a rune.",
+            "link": "https://pkg.go.dev/unicode/utf8#FullRune"
+        },
+        {
+            "sim": 0,
+            "sig": "func nettest.TestableAddress() bool",
+            "summary": "TestableAddress reports whether address of network is testable on the current platform configuration.",
+            "link": "https://pkg.go.dev/golang.org/x/net/nettest#TestableAddress"
+        },
+        ...
+    ]
+}
+```
+
+### Build and run frontend
+
+Ensure that you have [Go](https://go.dev), [Task](https://github.com/go-task/task), [Node.js](https://nodejs.org), and [Binaryen](https://github.com/WebAssembly/binaryen) installed.
+
+Then, execuate the following commands:
+
+```sh
+$ task wasm-exec syntaxck
+$ corepack enable
+$ pnpm install --frozen-lockfile
+$ cd frontend
+```
+
+If you don't want to have local Goggle proxy, you can specify your already-deployed endpoint by setting `VITE_EXTERN_ENDPOINT` variable.
+
+```sh
+$ echo 'VITE_EXTERN_ENDPOINT=<type your endpoint url here>' > .env.production
+```
+
+Then, run!
+
+```sh
+$ pnpm dev
+# Or, to use an external endpoint:
+$ pnpm dev --mode production
+```
+
+For building the frontend for deployment or serving:
+
+```sh
+$ pnpm build
+```
+
 ## :memo: TODO
 
 -   [ ] Index