Add deprecation notice for this repo

OLD_README.md

@@ -0,0 +1,46 @@
+# TypeScript LSIF indexer
+
+This is a copy of the old README for this project.
+
+## Installation
+
+```sh
+npm install -g @sourcegraph/lsif-tsc
+# OR
+yarn global add @sourcegraph/lsif-tsc
+```
+
+## Indexing your repository
+
+After installing `lsif-tsc` onto your PATH, you can invoke it with all of the arguments that are available to `tsc`.
+
+Index a TypeScript project by running the following command in the directory with your `tsconfig.json`.
+
+```
+$ lsif-tsc -p .
+..............
+46 file(s), 2787 symbol(s)
+Processed in 3.236s
+```
+
+Index a Javascript project by running the following command.
+
+```
+$ lsif-tsc **/*.js --AllowJs --checkJs
+................................
+295 file(s), 65535 symbol(s)
+Processed in 51.732s
+```
+
+The previous command relies on shell expansion to pass a list of filenames to the underlying TypeScript compiler. There is a limit on the number of files that can be passed as a command line argument, so it may be necessary to first dump the project filenames into a temporary file, and load that, as follows:
+
+```
+ls -1 **/*.js > inputs.txt
+lsif-tsc @inputs.txt --AllowJs --checkJs
+```
+
+Use `lsif-tsc --help` for more information.
+
+# Legal Notices
+
+This project began as a bugfix fork of [microsoft/lsif-node](https://github.com/microsoft/lsif-node) and therefore was originally authored by Microsoft. This code was originally and continues to be released under the [MIT License](./LICENSE).

README.md

@@ -1,46 +1,5 @@
-# TypeScript LSIF indexer ![Beta](https://img.shields.io/badge/status-beta-orange?style=flat)
+# Deprecated: TypeScript LSIF indexer
 
-Visit https://lsif.dev/ to learn about LSIF.
+This project is no longer maintained. Please use [lsif-typescript](https://github.com/sourcegraph/lsif-typescript) instead.
 
-## Installation
-
-```sh
-npm install -g @sourcegraph/lsif-tsc
-# OR
-yarn global add @sourcegraph/lsif-tsc
-```
-
-## Indexing your repository
-
-After installing `lsif-tsc` onto your PATH, you can invoke it with all of the arguments that are available to `tsc`.
-
-Index a TypeScript project by running the following command in the directory with your `tsconfig.json`.
-
-```
-$ lsif-tsc -p .
-..............
-46 file(s), 2787 symbol(s)
-Processed in 3.236s
-```
-
-Index a Javascript project by running the following command.
-
-```
-$ lsif-tsc **/*.js --AllowJs --checkJs
-................................
-295 file(s), 65535 symbol(s)
-Processed in 51.732s
-```
-
-The previous command relies on shell expansion to pass a list of filenames to the underlying TypeScript compiler. There is a limit on the number of files that can be passed as a command line argument, so it may be necessary to first dump the project filenames into a temporary file, and load that, as follows:
-
-```
-ls -1 **/*.js > inputs.txt
-lsif-tsc @inputs.txt --AllowJs --checkJs
-```
-
-Use `lsif-tsc --help` for more information.
-
-# Legal Notices
-
-This project began as a bugfix fork of [microsoft/lsif-node](https://github.com/microsoft/lsif-node) and therefore was originally authored by Microsoft. This code was originally and continues to be released under the [MIT License](./LICENSE).
+See [OLD_README.md](OLD_README.md) for the unmaintained documentation on how to use this project.