Fix broken link in Gridded user guide
"The difference between uniform, rectilinear and curvilinear grids is best illustrated by the figure below:\n",
"\n",
"<figure>\n",
- " <img src=\"http://www.earthsystemmodeling.org/esmf_releases/public/ESMF_6_3_0r/ESMC_crefdoc/img9.png\" alt=\"grid-types\">\n",
- " <figcaption>Types of logically rectangular grid tiles. Red circles show the values needed to specify grid coordinates for each type. Reproduced from <a href=\"http://www.earthsystemmodeling.org/esmf_releases/public/ESMF_6_3_0r/ESMC_crefdoc/node5.html\">ESMF documentation</a></figcaption>\n",
+ " <img src=\"http://earthsystemmodeling.org/docs/release/ESMF_8_1_1/ESMC_crefdoc/img11.png\" alt=\"grid-types\">\n",
+ " <figcaption>Types of logically rectangular grid tiles. Red circles show the values needed to specify grid coordinates for each type. Reproduced from <a href=\"http://earthsystemmodeling.org/docs/release/ESMF_8_1_1/ESMC_crefdoc/node5.html\">ESMF documentation</a></figcaption>\n",
"</figure>\n",
"\n",
"\n",
