docs: revamp installation docs for esm and umd (#1788)

* docs: revamp installation docs for esm and umd

Document recommended install paths across the main guides and package
READMEs for rrweb, @rrweb/all, @rrweb/record, @rrweb/replay, and
rrweb-player.

Clarify three usage modes: bundler/npm, browser no-build with
import maps and +esm, and legacy UMD fallback.

* Apply suggestions from code review

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

* Apply formatting changes

* Apply suggestion from @eoghanmurray

Co-authored-by: Eoghan Murray <eoghan@getthere.ie>

* Apply formatting changes

* docs(all): streamline README usage section

Move the guide link next to the import example and remove the
duplicated Usage section to keep docs concise and easier to scan.

* docs(readme): update gzip size badges in zh-cn readme

* docs(plugins): update readme imports to scoped esm packages

Replace `rrweb` default imports and `rrweb.Replayer` usage with
`@rrweb/record` `record` and `@rrweb/replay` `Replayer` in plugin
usage examples.

Also update canvas WebRTC plugin imports to scoped `@rrweb/*`
package names to keep docs aligned with current package structure.

* docs: update docs to prefer scoped esm packages

replace `rrweb` default import examples with `@rrweb/record` and
`@rrweb/replay` across recipes and guides in en/zh-CN.

clarify package selection for new integrations, add `@rrweb/all`
convenience guidance, and refresh CDN/style import snippets for ESM and legacy UMD compatibility.

---------

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>
Co-authored-by: Eoghan Murray <eoghan@getthere.ie>

docs/recipes/cross-origin-iframes.zh_CN.md

@@ -8,7 +8,9 @@
 在父页面中启用录制跨域 iframe:
 
 ```js
-rrweb.record({
+import { record } from '@rrweb/record';
+
+record({
   emit(event) {}, // 所有事件都将在此处发出，包括来自跨源 iframe 的事件
   recordCrossOriginIframes: true,
 });
@@ -17,7 +19,9 @@ rrweb.record({
 在您的子页面中启用重放跨域 iframe:
 
 ```js
-rrweb.record({
+import { record } from '@rrweb/record';
+
+record({
   emit(event) {}, // 这是 rrweb 所必需的，但子页面不会发出任何事件
   recordCrossOriginIframes: true,
 });