[doc/book] Rename crates-io.md to publishing.md

Author: behnam

src/doc/MIGRATION_MAP

@@ -2,7 +2,7 @@ index.md book/src/SUMMARY.md book/src/getting-started.md book/src/getting-starte
 guide.md book/src/guide.md book/src/guide/*.md
 build-script.md book/src/reference/build-scripts.md
 config.md book/src/reference/config.md
-crates-io.md book/src/reference/crates-io.md
+crates-io.md book/src/reference/publishing.md
 environment-variables.md book/src/reference/environment-variables.md
 external-tools.md book/src/reference/external-tools.md
 manifest.md book/src/reference/manifest.md

src/doc/book/src/SUMMARY.md

@@ -22,7 +22,7 @@
     * [Configuration](reference/config.md)
     * [Environment Variables](reference/environment-variables.md)
     * [Build Scripts](reference/build-scripts.md)
-    * [Publishing on crates.io](reference/crates-io.md)
+    * [Publishing on crates.io](reference/publishing.md)
     * [Package ID Specifications](reference/pkgid-spec.md)
     * [Source Replacement](reference/source-replacement.md)
     * [External Tools](reference/external-tools.md)

src/doc/book/src/reference.md

@@ -10,7 +10,7 @@ The reference covers the details of various areas of Cargo.
 * [Configuration](reference/config.html)
 * [Environment Variables](reference/environment-variables.html)
 * [Build Scripts](reference/build-scripts.html)
-* [Publishing on crates.io](reference/crates-io.html)
+* [Publishing on crates.io](reference/publishing.html)
 * [Package ID Specifications](reference/pkgid-spec.html)
 * [Source Replacement](reference/source-replacement.html)
 * [External Tools](reference/external-tools.html)