Like mentioned in Customization - React Component, Dochameleon merges custom and core components together at runtime. This makes further customization possible.

Let's say you don't like sidebar at the left side for docs. Just copy components/docs/DocsLayout.js from core library to website/components/docs, then modify render function to switch the order of sidebar and content.

    return (
      <Page site={site} title={title} description={content.trim().split('\n')[0]}>
        <Row>
          <Col xs={12} md={8} lg={9}>
            <Doc site={site} title={title}>{content}</Doc>
            <PrevNext site={site} metadata={metadata} />
          </Col>
          <Col xs={12} md={4} lg={3}>
            <DocsSidebar site={site} metadata={metadata} />
          </Col>
        </Row>
      </Page>
    );

Now npm run start see the sidebar is on the right side.