fix stac-spec links (#1276)

Author: agoddard

docs/src/examples/notebooks/Working_with_STAC.ipynb

@@ -12,7 +12,7 @@
     "\n",
     "> The SpatioTemporal Asset Catalog (STAC) specification aims to standardize the way geospatial assets are exposed online and queried. A 'spatiotemporal asset' is any file that represents information about the earth captured in a certain space and time. The initial focus is primarily remotely-sensed imagery (from satellites, but also planes, drones, balloons, etc), but the core is designed to be extensible to SAR, full motion video, point clouds, hyperspectral, LiDAR and derived data like NDVI, Digital Elevation Models, mosaics, etc.\n",
     "\n",
-    "Ref: https://github.com/radiantearth/stac-spechttps://github.com/radiantearth/stac-spec\n",
+    "Ref: https://github.com/radiantearth/stac-spec\n",
     "\n",
     "Using STAC makes data indexation and discovery really easy. In addition to the Collection/Item/Asset (data) specifications, data providers are also encouraged to follow a STAC API specification:  https://github.com/radiantearth/stac-api-spec\n",
     "\n",

docs/src/examples/notebooks/Working_with_STAC_simple.ipynb

@@ -13,7 +13,7 @@
     "\n",
     "> The SpatioTemporal Asset Catalog (STAC) specification aims to standardize the way geospatial assets are exposed online and queried. A 'spatiotemporal asset' is any file that represents information about the earth captured in a certain space and time. The initial focus is primarily remotely-sensed imagery (from satellites, but also planes, drones, balloons, etc), but the core is designed to be extensible to SAR, full motion video, point clouds, hyperspectral, LiDAR and derived data like NDVI, Digital Elevation Models, mosaics, etc.\n",
     "\n",
-    "Ref: https://github.com/radiantearth/stac-spechttps://github.com/radiantearth/stac-spec\n",
+    "Ref: https://github.com/radiantearth/stac-spec\n",
     "\n",
     "Using STAC makes data indexation and discovery really easy. In addition to the Collection/Item/Asset (data) specifications, data providers are also encouraged to follow a STAC API specification:  https://github.com/radiantearth/stac-api-spec\n",
     "\n",